I would say you should not release them as you dont own copyright or have the original designers permission. You could MAYBE share them with someone else who owns the printed kit. However also keeping in line with the copyright you should technically only build one model for each copy of the kit you own. Of course for your own personal use I dont see it as a huge deal since you are making each one unique for your own purposes.
On a side note, maybe you can try to contact the original designer/publisher with your repaints and reworked models and maybe they will grant permission as its kinda free advertising for them
Chris