Thanks everybody.
Regarding my concerns - this model has a very low online presence, and that made me suspicious. A few similar ones popped up, but they had no Japan marks on the dial. I don’t remember where I got the notion about this model having a Swiss movement. Perhaps I saw a different model with similar features.
As for the stainless steel issue, I guess that the 1977 ad takes a little bit of liberty, as ads tend to do (probably Truth in Advertising laws were less harsh back then, too). Probably just the bracelet was stainless steel. I have come across other vintage watches that had stainless steel bracelets paired with base metal cases, though I can’t really say that I understand the logic behind this choice. If you go for durability, go all the way, fellas.
Finally, some good news. On my most recent search I found the second colorway of that 1977 model, photographed for sale online. The dial on that watch is marked T Japan T too! The marks on caseback are also the same as my model. I think that pretty much wraps it up as far as verification goes, right?
