Update on the 6085, guys.
It turns out that it does have SKCM Green.
The seller sold it to me after we worked out a deal, but it wasn't cheap. Either way, these are kind of oddities, so I wanted to have one. They're probably a lot harder to come by than DocuTechs, which was incentive to shell out.
Anyway, this, combined with another user named Terrycherry on Deskthority also finding a damaged 6085 from 1993 from a junkyard which also had pine green, shows that:
1) Date is the most significant thing on these keyboards, and the DocuTechs are almost certainly just repackaged 6085 keyboards. If the date is 1990 and up, it's likely going to have SKCM Green.
2) Because of the jump from SKCM Brown to SKCM Green in the 6085, I think we have strong evidence to show a connection between the two. It's like the relationship of SKCM Blue > SKCM White or SKCM Orange > SKCM Salmon.
Secondly, it seems that DocuTech keyboards can have pine SKCM Green switches from 1990-1994.
Nateth helped me out here.
As you can see, the ICs have timecodes for 1994 and the stamp on the connector is also marked "94."
So, I would say that Nateth's pine DocuTech is from 1994. Maybe it was repaired in 1997 and they put it in a 1997 case or put a new label on it then, which would explain the lone bamboo switch.
So far, we've seen pine SKCM from 1990 and 1991 with my two Docutechs. 1992 from jacbolus' Docutech and the above 6085. 1993 from terrycherry's 6085, and 1994 from Nateth's DocuTech.
This filled a bunch of gaps in the timeline. Every board I've seen from 1995 on up has had bamboo, so 1994 must be the cut off year. Now we know. If only we could see some more from 1994 just to see if it varies at all.
The last thing to figure out is exactly how long DocuTech keyboards were produced.