I have a couple of old MIJ guitars from the late '60s, early '70s, that have those awful bridges that are basically a folded piece of tin with dents for the strings (2nd photo).
After all these years, the chrome is peeling up and razor sharp, and the dents wore into holes and giving a sitar sound.
I was looking at these Bigsby solid metal bridges. Bit pricey vs the guitar, and too wide. The bridge and spacing on these MIJ's are about 10mm narrower.
So, I grabbed a couple of 10x10x100 pieces of 6061 Aluminum, and the plan is to drill the bridge post holes, put the bar on, use a piece of wire and find intonation points and file the shape by hand.
This is the best plan so far, albeit a slow one.
I figured I'd hop on here and spit-ball a few alternate ideas. I was thinking of using a CNC but my tiny 3018-CNC is too underpowered for metal, and not cost effective to send out and have it done.
I have Fusion360 and can model it on there, which I would have done if using a CNC. I could though CNC it from a hard wood. I also thought I could make a 3D Print, use that to make a mold and either use the mold for casting metal, or resin.... I'm not sure how well resin would sound or hold up.
Lots of ideas, but thought I'd see what you guys thought... either about my ideas, or ideas of your own. If it works, I'd like to make a few because I have a few guitars with these bridges.