Hi Dave
You are in Durban, a big city if I understand correctly? I am in Ashburton, a country town with the nearest city, Christchurch, still recovering from a nasty earthquake.
In this town I can buy all manner of machines and potions for caring for sheep and cows, any type of irrigation system and tractors in any size from kids toys to ones I can stand beside and look up at the crankcase. But no shops carry things like micrometers!
We also have quite liberal customs and import regime which is good as we have a huge range of stuff available nowadays but the downside is that any man and his dog can get on his laptop and import whatever he likes to sell on line. For example I can buy an oil filter for a Mazda in a nice blue and white cardbox box, cheap too, but it is only when I look close that I see the name on the box is actually 'Mazdo'! So when the man in the local tool shop says he can get me 'Vertex' brand micrometers in a boxed set when the Vertex Taiwan web site does not show such things I naturally become a little cautious.
