Txbumper, I believe they were into Brasilian S/B a few years before, but even then, I'm not sure if solid. This was supposed to be a stripped-down dread well under the Jumbo and the Dove on their price list, so the laminate makes sense.
I'd like to correct some inaccuracies here about the Gibson Heritage.
The earliest Heritage models were solid Brazilian rosewood in the mid '60s. This changed to laminated Brazilian rosewood in the late '60s. These early Heritage models were less ornate than the Heritage Custom from the early '70s, which is what the OP's guitar in question is (as clearly indicated on the inner label). There apparently was a non-Custom version for a few years that had laminated EI rosewood back & sides, but the Heritage Custom, which is the only version I've repeatedly seen first-hand from this period, had solid rosewood back & sides. The Blue Book of Acoustic Guitars has lots of misinformation, and this particular error continues to reappear with each new volume.
In the late '70s, I owned this exact guitar - an early '70s Heritage Custom. They were actually one of Gibson's most expensive instruments in the catalogs I have, and not at all a stripped down dread. Along with being solid rosewood, the fingerboard & bridge were ebony. Somewhere I still have a price list, and as I recall, only the J200 cost more.
As for the guitar itself, these '70s instruments had Gibson's over-built double-X bracing, which often resulted in a very stiff & less resonant top. But generalizations are meant to be broken, and some Gibsons from this period sounded wonderful (including the one I owned).
But the bottom line regarding this model is that it was produced during what is considered to be Gibson's low point in overall acoustic build quality. You might get lucky & find a good one, but, imho, Gibson's built from 1999 to present are the ones to focus on & seriously consider. In '99, the model line-up was revamped with a major turn towards iconic models from the '50s & '60s, including jumbos, small jumbos, round shoulder dreads, and so on.
So if you're thinking about a Guild F50 jumbo, you might also keep an eye out for any recent version of the Gibson J-100. This model has been made in maple, mahogany, and bubinga. They quite often sound fabulous, and are frequently priced under $1500 used. I happen to own a maple J-100 made in 2000, and it's a serious keeper (along with my maple '94 Guild JF-30, which tonally has a very similar vibe).
Best of luck in your search, and enjoy the process!