What did G&L do to this body?

Just looks like walnut stain to me

 

Everything repaired is a thing these days. Roasted Maple, roasted ash, roasted Alder....Warmoth actually offers them all.

 

I like That roasted swamp ash!

I wonder what finishes would look like on top of them.

 

FIFY. And yeah, roasted is getting to be a pretty big thing these days:

• More "old wood" tone - as wood ages, the remaining sap and resin slowly leaves the instrument (at least when it hasn't been coated an inch thick in poly as Fender is wont to do), which "opens up" the instrument's acoustic tone. Roasting is meant to simulate this process.
• More stable - the overdrying of the roasting process makes necks less susceptible to changes in climate, giving you better tuning and setup stability (one major reason necks were the first piece to get this treatment)
• No finish needed - Because of the climate tolerance, you don't need to seal roasted wood, so if you like the feel of bare wood under your fingers this is the way to go.
• Nice aesthetics - The roasting darkens the color, of course, but also helps to bring out grain and figuring, which is coming into style as an "old made new" look, similar to making instruments from reclaimed wood.