My 62 RI came with one already fitted, but I took it off as I didn’t use it, I do play with the thumb but not in that position, i Know a few people that have fitted them just for vintage decoration purposes 🙂
I can remember hearing, peaches around 1977 when I was first having bass lessons, fantastic Bassline and a great band , and I think go buddy go was on the b side, I’ve still got the single in the loft 🙂
I would definitely go down the route of making one , if you get the foam at the right depth you need for the case , you can draw round it with a felt pen and as baxlin says cut it out carefully with a craft knife and glue it in , and if you really wanted to you can cover the foam with a suitable material of your choice to really finish it off 🙂
Mine just hangs on the wall now, but back in the day I used to play mine through a , HH ic 100s head with 2x15 HH speakers , I used to rumble my mums house down 😁