www.KitGuitarsForum.com

At any rate, by gut still says that the hole is from transferring the volume knob. They may have put a new pickguard on the guitar, which would have covered the original hole.

Ok, I was bored and poked around the web. That hole is to accommodate the spring on another type of Harmony tremolo. Here’s a pic. Screw holes also match holes in body. Perhaps It is the “Roy Smeck H73”.

Wow you guys are good. The back of the guitar still has the same red paint. I think you nailed it.

I WAS a vibrato! I wasn't sure and I've not had time to research. Good job Teeterman!

I confess that I have an affection for the unsophisticated, sometimes clunky hardware you see on these cheaper instruments.

conveniently that exact bridge was available for sale on ebay and I got it. I think your pic was the ebay pic. what a coincidence. pickups and other parts should be easy to get. any ideas on a neck? there are a couple Harmony necks on ebay which seem similar to what I need but they are a little pricy (and obviously beat up given their age).

Reverb.com has a “Harmony Roy Smeck H73 Red”, which has many pictures of the guitar in the listing. Good reserch. You might look for parts there.