Ok, Thanks so much for yall's input. After searching today for a 15mm coupler nut and a 15mm bolt which I do not think they make, and then some concern about the coupler nut coming unscrewed when the bike is being pedaled, I decided to try something else. In the previous post I showed a pic of what looks like a large spot weld on the axle flange. I decided to try to drill out the weld, and WOO HOO it worked. I drilled it out and the flange felt a little sloppy on the shaft, after a couple of hits with a hammer, the flange slid off the axle. I will have a little modification to the flange and then I'll tack it back where I want it to go. The axle is gonna be a perfect fit once I place the flange where it needs to be. Thanks again for all of yall's great ideas, they really got me thinking, which is what my brain needs sometimes.