The handouts from the New Equipment Training Branch may be the best jackpot, Mercedes usually does color schematics of various vehicle systems that are quite helpful in understanding how they work and for diagnosis. The manuals are sadly short on "big picture" drawings. I have heard of but not seen SEE specific schematics thanks for offering to post. I do have a high resolution 11x17 color scanner and if there are some larger size schematics I would be willing to pay to have them scanned if they appear of value to SEE folks. PM me and we can talk specifics.
The other manuals are out there on the internet I will check my revision dates and list them. I think I downloaded mine from Pirate 4x4 site. Expedition Imports also has a download page for these manuals. I didnt check the rev dates but expect they are the newest available. Here is link to the 419 page and there are some links to these manuals
https://expedition-imports.com/419Parts
TM5-2420-224-12 Dated 28 July 1993 - Same as mine 28 July 93
TM5-2420-224-10 Dated 28 July 1993 with change 2 - Same as mine 28 July 93
TM5-2420-224-20-1 Dated 28 July 1993 with change 2 - Not sure on this one, mine is dated 28 July 1993 but I dont see "change 2" listed
TM5-2420-224-20-2 Dated 28 July 1993 with change 2 - Not sure on this one, mine is dated 28 July 1993 but I dont see "change 2" listed
TM5-2420-224-24P-1 Dated 30 Nov 2001 - Same as mine
TM5-2420-224-24P-2 Dated 30 Nov 2001- Same as mine
TM5-2420-224-34 Dated 28 July 1993 with change 1 Same date as mine but no "change 1" listed