[ Ref. John Grant in 231206 MMD ]

I've used a snap fastener kit similar to this one for my MGB sports
car, carpet, and convertible top. They are identical to the ones on
the bottom of my Steinway Duo-Art:
https://generaltools.com/snap-fastener-kit 

Amazon has some other more fancy versions with a crimp tool rather
than a die.

Best wishes,
Ed Chaban