I will defer to you or anyone else who knows more about Shoguns as my internet search capabilities are limited or simply produce insufficient results. I saw both a 7 and 8 in either number set (early in the order), so that got me to educatedly guess those years, but narrow down no further.

Was Shogun on a downward trend regarding sales volume as it progressed through the '80s? Could that be one of the reasons there is so little info on these (hence my detailing of frame geometry and large photos for future C&V enthusiasts/riders)? There aren't a lot of triple triangle Shoguns around (though I'd love to have an idea!), to say nothing of traditional offerings around the same period. It seems they were a bit more common in the '70s and early '80s. They must have tapered off decently, but this is a wild guess on my part.

Somehow, though, in our fity-ish person company, there are two triple triangle Shoguns. An '85/'86 pink/warm grey metallic 1000 with Shimano 600, and mine. When my coworker bought hers, it had the wackiest tall and adjustable stem and bar combo, which I helped her in remedying via some spare parts I had.