reply #8 has a pic of a frame that is 3D printed. Got any hobby or computer geek friends that has a 3D printer?
I think I recollect someone that that has a mention he about custom work. In any case it shouldn't be hard to find someone local that might be able to brew something up for you.
Also, today there are many 3D printing services around, in particular in Ireland https://3dprintingireland.com/3d-printing/ , for example. You upload the files and you receive a (usually) well printed part. We have excellent free tools like FreeCAD.
Aso we may instead print the mold... by molding the part we may use a technical resin mixed with cut fiber glass, or placing a perforated metal plate in the mold, obtaining an impressively reinforced part. But all this requires liking DIY and making a substantial effort, still it can be quite rewarding, while first DIY parts are challenging, later you make anything fast/easy, just like riding a bicycle.