That's right, Jon at Swineshead makes a thinner bobbin out of plastic but I also seem to remember that the wooden tops aren't just tops, I'm sure Jon told me they're complete bobbins.Either way they're a design that's particular to Swineshead so won't fit ontop regular PAF baseplates lile ours.
It is possible to get tops CNCed out very easily but I've avoided going down this route as so many other makers are doing it and also, I personally don't like the look. Gibson tried it years ago, covering everything in wood on a fancy LP and it never took off, it looked too much, literally like you were playing a coffee table :lol: