So, fitting a B3 to a Rickenbacker 330 is problematic!! Firstly the sloping deck means the body is a bit thin for the tailpiece hinge plate to mount. The B3 is also a bit long to fit on the sloped part of the deck. The solution is from TownerUSA
Using these two parts has allowed me to position the hinge plate of the B3 higher, so that it does not protrude past the back of the body. It makes it level with the tailpiece parallel to the flat top of the body, though the space between the sloping deck and the B3 tailpiece is not the most elegant. I think this will be functional and once strung prove to be stable.
A further problem is the proprietary Rickenbacker strap buttons. These have the button attached to the screw and the screw is not long enough to reach through the Bigsby hinge plate, V.Block and thread into the body. The screw is also a larger diameter than any aftermarket strap button screws so you cannot simply swap them over. It is also a different thread with the wood in the body threaded to match. The Rickenbacker screw is however a simple Machine screw thread. So at this point my “less than elegant” solution was to drill out an aftermarket strap button to fit a 50mm machine screw which threads directly into the body. I will be looking for a more suitable machine screw. This is functional but not pretty. Pictures below show the V.Block installed on the Bigsby Hingeplate and then mounted on the body. Note the “not so elegant” machine screw and strap button.
I have the complete Towner and Bigsby Kits in both stainless steel and gold in stock.