Man, I found this thread through Google and just had to make an account to reply (should’ve already had an account; I own this guitar, a songbird, and an F-512). I was reading the title of the post here and thought to myself “this must be some other me from an alternate reality” - this is exactly what happened to me earlier this year.
Purchased a “D-50” from a family that didn’t know any better, and the guitar turned out to be a G-75. Except mine has a double pick guard from factory. The story was told to me as such: the guitar was owned by a player in the Philadelphia Orchestra, then sold to its previous owner who passed away where it then sat as an heirloom.
The case may be cooler than the guitar, with some original D.B Cooper newpaper clippings glued onto it from the previous owner. Such an oddly shaped case too. Only things I changed were the bridge pins and installed the L.R Baggs Anthem.