Each year Delco-Remy published a collection of Service Bulletins in an Electrical Equipment Operation and Maintenance Handbook. This book is number DR-324. They also published a separate collection of Service Bulletins with the Test Specifications needed to do the actual tests, repairs, and adjustments.
On January 1, 1956 they published a version of these 2 books which collected all the prior annual versions of this information into 2 books so you didn't need all the individual prior year copies. After that they published annual updates again. Prior to the 1956 edition the individual Bulletins were only updated as needed. As an example I found the 11-20-49 version of DR-324 on line. The Generator Operating Principles Bulletin 1G-100 in it is dated 1-22-46 which superseded one dated 12-28-38.
I couldn't find the test spec book on line and finally purchased a 1956 copy from a company in Israel. It came by mail in about a week
For the Generator there are 3 bulletins. I've shown the first pages of each here. The three are:
1G-100 Operating Principles Generators, 7-22-46, 4 pages
1G-125 Types and Designs of Generators, 12-16-46, 6 pages
1G-150 Adjustments, Test and Maintenance of Generators, 2-4-49, 12 pages
To test the generator there are 2 Service Bulletins.
The first is 1G-180 Numerical Index - Generator Service Test Specifications, 1-1-56, 7 pages. You use this one to look up the specific generator model number to find the applicable specializations in the second bulletin. On the C-85-12 the generator model number is 1101890. It's near the bottom of the first column of page 2, below. It shows that the test spec to use for this model is 1814, the generator turns clockwise, and the brush spring tension is 24 ounces.
The second Generator Test Bulletin is 1G-185 Generator Service Test Specifications, 1-1-56, 6 pages. It gives the Field Current, Output Amps and Volts at the rated RPM. as well as other information. Spec 1814 for this generator is on page 5, below.
For the starter (Cranking Motor) there are 4 Service Bullletins:
1M-100 Operating Principles - Cranking Motors, 7-24-46, 4 pages
1M-120 Cranking Motors Using Overrunning Clutch Drive, 8-30-46, 4 pages
1M-130 Cranking Motors Using Dyer Drive, 9-9-46, 4 Pages
1M-150 Adjustments, Test, and Maintenance of Cranking Motors, 3-2-49, 13 pages
To test the starter there are, again, 2 Service Bulletins.
The first is 1M-180 Numerical Index - Cranking Motor Service, 1-1-56, 4 pages. Again, you use this one to look up the specific starter model number to find the applicable specializations in the second bulletin. On the C-85-12 the starter model number is 1109656. It's near the bottom of the third column of page 4, below. It shows that the test spec to use for this model is 2377 and the starter turns clockwise.
The second Cranking Motor Test Bulletin is 1M-185 Cranking Motor Service Test Specifications, 1-1-56, 3 pages. It gives the Brush Tension, Cranking Amps, Volts, and rated RPM. as well as other information. Spec 2377 for this starter is on page 3, below.
The Voltage Regulator used on the C-85-12 is Model N0. 118736. The Service Bulletin for it is 1R-116 D-R 1118300 Type Two - and Three - Unit Regulators, 2-8-49, 10 pages.
The Regulator Service bulletins are:
1R-180 Numerical Index - Generator Output Control and Relay Service Test Specifications, 1-1-56, 5 pages
1R-185 Generator Output Control and Relay Service Test Specifications, 1-1-56, 10 pages.
The test spec or the 118736 Regulator is 2165 which is in Table 2 of 1R-185.
While it took several weeks to find all the Bulletins, it seems better to service the units based on the Bulletins rather than a lot of well meaning advice which may or may not be reliable. Delco-Remy went to a lot of trouble to provide these and a lot of GM vehicles and Continental Motors were serviced using them.