Quite some time ago, 1982 in fact, I was to go on a work trip from New Zealand to the UK, a quite remarkable thing in our department at the time. A few days before I was due to leave one of my fellow workers came to me holding a page torn from a motorcycle magazine. He asked if I could find a particular shop advertised in the magazine and buy for him a special left hand scroll type cable control of a particular and much desired brand for his Douglas motorcycle. I had only vaguely hear of such a marque but he assured me the shop would have what he needed and when he had it he would be able to complete the restoration.
A few weeks later I devoted one Saturday in London to his request, I took the tube to a station on the very street where the shop was and checked the street numbers finding I had about 1000 numbers to reach the shop, but it was a nice day and I was at my leisure to go on a nice long walk. I walked right up the street as the numbers got slowly closer until the street stopped at a park. Not having a map I assumed the street continued on the other side of the park which I crossed to find there was a canal on that side and no sign of my street so I retraced my steps. Feeling I had failed I began to walk down the other side and was astonished to see the numbers were still decreasing! WTF? The numbers went up one side of the street and down the other!

Needless to say I found the shop about 50 metres (yards) from the tube station!
The shop was actually open with an old codger behind the counter. I told him what I wanted and he showed me a beautiful new left hand scroll type handlebar control with the desired brand name on it. Then he said "Here, I will put it in a box for your friend!", he reached under the counter and placed a little blue cardboard in front of me. I paid the money and we discussed life in the colonies for some time. Apparently he has spent some time between ships in Australia.
I got home to NZ and took the little box to work to give my friend and just before handing it over I opened it for the first time to find not the nice new Left Hand control but a used right hand with peeling chrome of some generic make. I was right pissed off and rather embarassed too but my collegue accepted it in good grace while I mumbled various curses we have in this part of the world and normally reserved for the worst of those from the "Old Country".
Twenty years later I met my ex-collegue on the street and as part of making conversation I asked after his Douglas. He sighed and said I should come to his house and take it away.
He had not actually done any restoration but had dismantled the bike and left it in a small shed that had over the years tumbled down around it. We had to practically scratch around in long grass to find all the bits but I got them all except for a couple of minor items.
So thats how I came to have a pile of bits that had once been a Douglas 80 Plus 350cc horizontally apposed, transverse twin with torsion bar rear suspension and 'Radiadraulic' suspension on the front.
He had the original registration papers and an application form for the London Douglas Motor Cycle Club. I joined the club and they were a great help with many restoration issues including quite a few minor spares. They also told me which day the bike had been completed (25 Aug 1952) at the Bristol factory and they advised the factory records did not record who the bike had been delivered too! Stolen from the factory, maybe! Not likely when I checked on the NZ owner, he was a NZ Isle of Man rider (Sid Jenkins) and had registered the bike in his home town in November of that year, just enough time to have bought it from the factory and shipped it to NZ as personal baggage which would have saved hundred of quid in taxes and duties. Exactly two years after first registration it was re-registered to someone else. Two years was the minimum time Sid would need to have 'owned' the bike to avoid the taxes and duties. I contacted Sid's widow who gave me the name of some of his friends but none of them could remember him ever having a Douglas, one said he doubted Sid would have ever got on something as small as a 350!
The Douglas now stands in my garage, looking pretty much original but converted to 12 volts and maybe a little more chrome than it would have left the factory with. It has all the 'third world country' options such as a side stand and air cleaner but I have done away with the high level exhaust (too hard to bend the pipes).
Douglas were once the biggest motorcycle maker in the world, that was during WWI, at that time they were building fore-and-aft twins and were quite strong in competitions until about 1930. They made engines for light aircraft too but not in any number. The company floundered and lost its way a couple of times and had a bit of a reprieve in WWII when they built small engines for fire pumps and it is claimed aircraft auxilary units. Their portable water pumps and generators were moderately sucessful around the world. The engine used in WWII was the basis for the post war bikes, fairly similar going through a few versions including the Plus 80 and the Plus 90. Their final bike was the Douglas Dragonfly with Earls front forks. They assembled Vespas for a while but by 1957 or so the company was history, too early to blame the Japanese.
Some things you will hear about Douglas bikes:
They were copies of BMW, err maybe, but Douglas were building horizontal twin bikes when BMW were carving wooden propellers for the Red Baron.
The Plus 80 and the Plus 90 were all the same, those that bench tested higher horsepower were classed as the Plus 90. I think I can confidently call BS on this one, unless they then stripped down the motors to change cams, etc.
Some American guy in the '20 was at a party in London when a young strumpet asked if he was going back to America by ship. He must have thought 'duh?' and flipped off a comment that he would be riding his motorcycle home. Another diner at the table said something to the effect that that could be arranged and it transpired he was a dealer or connected with the Douglas factory. A bike was made available and Robert Fulton did indeed ride his motorcyle as far as practical on this route home to America. It was an incredible journey and you can read his book One Man Caravan which is available from Amazon I believe.
(Sorry about the typos but I have been typing so long I am not inclined to proof read!)