Great idea placing the motor in that position. I'm thinking of the same mounting for one of my Maytag twins. I have several and I also have some Peerless gearboxes that could be mounted up on it's end under the engine connected by a clutch/chain/sprocket setup to the the trans and the sprocket out the side with three or five speeds to the rear wheel. The trans also has a little disc brake opposite the output sprocket. I also wanted to use a damaged flywheel I have with the outer rim and fins broken off. I would place two little fans at each cylinder driven off a belt on what's left of the flywheel. I used one of these transmissions on my "Four Wheel Project'' in the Tavern category. They are packed with grease and can be positioned however you want. I would obviously disable the reverse gear.
Anyway, great start on your project. Always glad to see someone using antique motors and bikes for special builds. After all Maytag motors aren't called multimotors for no reason, they were used on everything from washing machines to lawnmowers to generators, water pumps, compressors, etc.
Excellent find on the shaft drive. How many spokes do the wheels have? I'll have to keep an eye out for a future build.
I've been collecting old motors for 45 years or so. Let me know if I can help.
http://www.ebay.com/itm/Peerless-Tr...674?pt=LH_DefaultDomain_0&hash=item2a2a430102