A problem that pops up a bit lately is getting an oil tank for a 750 that will hold the proper sized battery. They were plentiful back in the 70s and 80s, but, not so any more... much like most 750 parts. Oil tanks with battery trays are plentiful for the HD Softails though, of course. You can use one of these, but the standard 12N14-3A battery for a 750 doesn't quite fill the opening and can bang around loose if you don't secure it. Here's a part I offer that can help in many ways.

By just drilling 2 holes in the tray of the oil tank and installing this bracket.. you will hold that smaller battery in place. Also, theres room for other electrics in there with it and those two holes are the same dimension as the mount holes of a Ricks Rectifier/ regulator to mount on the bottom of the oil tank You can use the oil tank to house your oil, battery and electrics.. all in one. t's made of stainless, so there's no need to paint or chrome it. No need for an electric box or battery box. You will however, have to mount the coils someplace, but that's usually the case with a standard electric box as well. I offer these as well as the other components on my parts page, towards the bottom of the page. Also, I offer a discount for the package. This is not meant to be a shameless plug..lolol.. but it's something that many guys find helpful and useful.