Hi!
Just a thought: my adjustable rear drop outs have a few numbers stamped in. Among others a '88. Could this be the year. Does it match in your cases? Also, my 3ttt stem has a 88 on it.
My serial number starts with 8, too.
But then, I've seen a 40th anniversary '88 Compact that differs from mine in that it has two bottle holders and a punmp thorn. Picture attached.

I've written to GIOS. Wait and see.

Cheers,
Guido