KZ750 frame modification question - lowering seat height

I just wish I could have found a mag wheel for the rear too, even after putting new spokes on. Those wheels look so neat. It also looks pretty cool with just a mag wheel on the front but I think eventually I'd like to find one for the rear. If they even exist? lol Im not in much of a hurry for that, putting the new tires on wasnt much fun either. I'll probably look again for a rear mag when its time to replace tires. unless something falls in my lap before then, parts for projects like this have a way of just manifesting themselves lol.