I have a kite trike and love it but sooner or later it will completely rust out and I like the way it rides. I want to get another one built whenever I can. Is there anyone who would undertake that project. I was thinking either stainless or steel with epoxy coating. The epoxy coating I could do my self with some spray epoxy paint I found at an auto shop. Right now I just want the rails and axle done.

Is there a a way to drill out a 20 mm bolt and thread it to 12 mm

20mm is larger than 12mm so you would not be able to drill it out as it is already to big for 12mm. You may want to contact Van and see if he has any rails and axles laying around. His are not stainless though, just steel. I think I have a set of kite trike rails in storage somewhere, I don't have a rear axle though.