Let me tell you the tale of the Sonex, the cheapest Gibson until recent years. With sales going downhill at the end of the seventies and Gibson falling out of fashion and being beaten by Japanese copies, the company decided to try a budget line. They had the necks made overseas, got hardware from japan and assembled them in the USA to keep the “made in the USA” tag.
The bodies were made of “resonwood” a mixture of glue and sawdust moulded around a tonewood core of mahogany that the neck would bolt(!) onto. Advertising materials would boast of the lengthy sustain this material sandwich could attain, to head off concerns around the bolt-on neck.
There were a few oddball models, but the Sonex line had three models.
The Deluxe was the cheapest and most common. Featuring Bill Lawrence designed “velvet brick” pickups, a three-piece maple and rosewood neck. The Standard model upgraded the pickups to dirty fingers (with coil taps) and the Custom model got the dirty fingers plus an ebony fretboard. There was also a model with the onboard moog electronics that were in the RDs at the time.
Mine is a Custom, someone has replaced the original black pickguard with a cream one and I swapped out the much corroded bridge piece. It’s about due for a new input jack too.
Gloriously beat up, heavy as hell and the DF’s sound pretty nasty. I love the neck on this. The frets are fucked but I think they’ve been shaved down to match the neck angle? Really flat by the nut and pretty much full at the body. Plays okay.
Anyway I asked because I have a "The Paul" from the same period, a close relative. It came with a harmonica bridge which was also corroded, although not that badly. Took a lot of searching to find something to retrofit. 
