Red: Different Axles??

I don't know why I'm even surprised when something should fit but doesn't.  I bought 2 new axle nuts on eBay (since Cycle Parts said they were discontinued).  The seller listed them as 90305-001-000, which matches what the '68 parts book has.

But when I went to swap them, I discovered both of Red's axles take 10mm nuts and the new ones were 12mm.

Then I checked the other bikes.  Roxy is the same with 10mm front and rear, but Viola has 12mm front and rear!

Are there 2 versions of the rear axle?  I knew there were 2 versions of the front, but how could it be 10mm when the parts book only ever listed a single type of nut??

Also replaced the front sprocket plate along with the two 6x10 bolts (funky screw/bolt combo).