I also had this timeline in mind. Thanks for confirming and for sharing this great scan. So 1987 seems a good spot for the Highlander bike.maybe "released" End of 1986 but for season 1987?
Also the Deore II hast to my knowledge been used from saison 1989 bikes onwards, not already 1988.
At least in the bicycle components complete line 1987 catalog the entire series is marked as "new"
In adding clues, we might end up with an answerI don't know why or where I've seen similar cabel guides, but this looks again very Italian.
Still hope that someone is solving this mystery.
I have found other italian brands with similar cable guide. It confirms they are generic and quite common on Italian bikes.I have very similar cable guide on a 1977 road bike, from Stelbel. It doesn't lead to the frame builder as cable guides might be generic. But it might be another clue regarding Italia.
The source https://steel-vintage.com/products/stelbel-master-light-road-bike-1977
View attachment 766285
Bike sems to have a steep seat angle. Short width saddles like turbo and flite feel better on steep seat angles. I see Unicanitors on laidback seat angle bikes like Potts and Cunninghams.I have added a Flite for now. But I might choose a Cinelli unicanitor, a Turbo or a Kashimax GTV. Don't know yet