Old Gibson laminated top braces ?

[thefishinmusician]

Never seen this on a Gibson....All the top braces are like this...Back braces are normal tapered single piece braces....Any clues ?

[Mike Kolb]

Hard to tell, but are those braces some sort of "sandwich"?  Almost like someone wanted to strengthen the existing top braces.   Do they run the length of each brace, out to the purfling?   Agreed, it's a mystery.

[thefishinmusician]

A sandwich....ALL the top braces have them the full length....All square like this...

[Roger Häggström]

I have seen a "kerfing" (with a lot of cuts in the spruce) topped with a thin layer of maple in 1930s L-30 Gibson archtops. Used in the one and main brace in the cut top. A horrible solution that kills tone, but is easy to shape when making the guitar...