Harry,
I've been wanting to comment about these wheels for a while, but have had health issue and so on. Make these in both orange and black, and maybe some in your nice dark red. Some may rather have red than orange wheels and almost all of the electric type locos have red wheels. And be careful on the shade of orange. I've seen some of these reproduction wheels on an original 90 year old loco that are a so loud shade of orange that they stand out like a construction workers "Hi Vis Safety Vest".
There are literally thousands of Flyer locos in need of these wheels. Many, if not most of the electric locos have these wheels. So plain hub electric loco wheels should sell very well, especially in red. Although, I have seen many original American Flyer electric locos that takes this wheel have original factory installed steam type wheels. People will still prefer plain spoke red wheels for their electric locos.
I'll take 2 sets in black as soon as have them available. I've had an almost mint 1st version 3300 steam loco that took these smaller wheels and die-cast rods that's been sitting in a box with it's 3301 tender just waiting for these wheels for a long time. I may ask around here for professional to install these wheels and maybe re-wire and assemble the new cast rods with the correct rivets and rivet press dies. It's a real rare version, especially in this condition (bright gloss paint with almost all of it's green stripes etc.). So I may pay someone to put it back together with the exact tools.