I took a look at our CO and we have a bunch of different Northern Telecom DMS Documentation binders. Stuff like Installation Manual (Module 00 to 18), Volume 3 Power-up Methods, DMS-10 Family OMP/RLCM Book 1, DMS-10 Family Volume 1 Generic: 400 Part 2. We also have a bunch of old CDROMs with documentation on them, as NT started just sending documentation like that instead.
But yeah there are books upon books of stuff here, and Northern Telecom isn't a company anymore from what I understand, so finding documentation is pretty limited if you don't already have an in.
I've been looking through everything we have (including the CDROMs from 2002-2003) but the main issue is that the publication numbers listed for the physical manual they need (03-4200) is quite different than the publication numbers for all of our stuff. Everything we have uses a publication number like 297-3601-450, so it's possible that installation manual is a separate, special manual you/the company installing the switch would have for the initial physical install and the rest of the publications assume you already have an installed DMS-10.
There's a chance we never even had that manual ourselves, if that's the case! I did find our original installation proposal documents - our DMS-10 was installed in 1989/1990 :)
But yeah there are books upon books of stuff here, and Northern Telecom isn't a company anymore from what I understand, so finding documentation is pretty limited if you don't already have an in.