Hi ed,
the noi cylinder has the fins directed so the air from the front cools the engine.
If you put the fan, the air won't be able to pass from right to left and most probably make no difference, and the fan will consume you 1/10 HP or so anyway.
I have always wondered why these reed valve cylinders didn't fit pre-1985 engines, it's just the transfers position?
About the V3 / V1 pipes, they are making custom pipes nowadays but they are struggling to compete to chinese 110 cc 4 stroke crap, and almost nobody buys 50 cc mopeds anymore snif snif