The old Yamaha SA5, SA20, SA30 and SA50 have a rosewood or ebony bridge base. The bridge base is quite a nice piece of workmanship and is not easily made from scratch. The bottom of the bridge is angled in two dimensions so that it follows the contours of the arched top it is resting on. It is screwed onto the guitar body while the posts are screwed into the bridge base to allow the metal Tune-o-matic to sit on top.
You can buy generic timber bridge bases at Stewmac or so for about $20, but they look different and their post spacing does not allow for an original Yamaha SA30 tune-o-matic.
I recently bought an old busted up SA30 with something that really could not be called an archtop bridge. It needed something better...
So I pulled the orginal bridge base from one of my SA30s and decided to copy it and make my own. Blimey, 3.5 hours later and I do have a rather nice (if I say so myself), brand new bridge base. Just need to source the screws and the posts but trying it with the original bits...
All fits perfectly on the old Superaxe and looks rather 'original'. Here some photos.
Top one is the original rosewood base.
Bottom view:
Fitted onto the SA-30 body:
With tune-o-matic fitted:
