Timo, my observations are the same: Tokai boards on 1978-1981 (not much experience outside this range) models have a far darker appearance than the Greco 1980/81 EGF models I've seen. That on itself doesn't explain what kind of wood was used on the Tokai's. But it seems to be very consistent in color and dark to an extent that grain lines are hardly visible. Stained or did they buy a large quantity of a certain species? I don't know. I have tried to decipher the Tokai catalogs on Vintaxe which are larger copies than here on the registry (thus readable) but there's so much text that it needs someone like Harold to make some sense out of it.
Regarding availability: Honduran mahogany is on the CITES list since november 16 1995, Brazilian rosewood since november 6 1992, so that's way later than the vintage Tokai's we're talking about.
Fujigen, one the leading guitar factories of that time in Japan, was using Brazilian rosewood on higher end models. There's proof of that in the Greco catalogs. So this type of rosewood was acknowledged for what it was in 1980 and because of that very likely that Tokai had the same knowledge as well, thus your 1979 Tokai could have a Brazilian board.
A good dendrologist should have no problems identifying your fretboard wood. Or you could visit Erik van de Haar, the guy you bought your Dr.Z amp from, when you're in the area again. Nowadays a luthier, he used to be a wood importer, has a huge stockpile of different wood types (you should see his stash of highly figured maple, out of this world!!) and has shown me all shades of Brasilian rosewood, nice guy!
