We had lost the fuel cap on our 763 bobcat and instead of buying I decided to print one.
The 2 parts was a tight fit for me, once pushed together i couldnt disassemble it, maybe some glue can help aswell. I printed and only tested with ASA filament. It has a central air channel to let out the pressure from the tank.
I recommend printing only the thread first and testing it to make sure it works for your machine.
The one on the photo has been working for almost a year without any problem.
The author marked this model as their own original creation.