Congrats, Always a thrill when our models run. 
Looks good, sounds great. Seems to be cycling through the hit and miss well.
I would probably try to get the revs down a bit more but that is more fiddling (modifications) as you thought.
Well Done.
John B
Thanks John, yes if it could miss a little more than hit I would be really stoked. I am watching as much as I can on YT picking up a hint here and there.
I made another dummy battery on the lathe with some delrin and brass and tried running it on just two AA batteries (3v) thinking that might make it run slower but it wasn't enough to fire it.
Those 'points' I think hold a bit of the key to slowing it down, but boy are they fiddly things!
Thanks again for the comment, really appreciated.