Harry, I'm not aware of any valid patents that apply to the servi-cycle. If there were any, they may have been assigned to Gary Wollard & he's no longer with us.
You should call & get to know Wayne Mahaffey, our one & only parts vendor (located in Alabama). He can give you a list of what's already on the market (he's made a lot of repop parts) and what still needs to be tooled to help support the brand.
I wish you a lot of success. We need more parts!!!
Mike Sal