Je's new bike?
Hi Je, nice classic frame! I agree about that aluminum frame, NO Engine!I have a Hairpin saddle (repop of the penny-farthing saddle) available that might look great on that. I'd run either red or white tires, do the tank, 36 tooth front sprocket (most early motorcycles had small people sprockets). I agree with the monark springer for it's style, but if you really want to ride it, I think I'd use a Shockmaster, the postwar version only! Cleveland Welding Company's springer absolutely rocks!
You might be able to slip in a toolbox, or make a "filler" plate to go between the bobbed rear fender to drive away a little more of the "Bicycle" look? If you do a bobbed rear fender it is easy to make a drop-stand, i do them all the time, and we kick-start our whizzers on them.
One of the main complaints I have about trying to make a repop of a vintage bike is all the kit stuff is so modern, and the engine is tiny, and uncomplicated. I like to add stuff that diverts from what came in that chinese box. I just made a brass muffler for my 08 prototype, it looks cool, sounds great, and I used a very special, sound deadening material inside that is very cheap, and easy to use (air).
As long as that frame is sound, it looks VERY good.
Mike