That tar was on a lot of MZ-2.
The batteries are a bubba thing as the TCS did not have batteries but used on of several power supplies.
Your TCS-5 is one of the earlier versions. There was some kind of significant change at TCS-8 and there are quite a few TCS-12 used.
You need manuals... at least one and maybe several.
Here are some... you find them on Ebay and some of the old radio and boat anchor (Navy radio) shops.
Manuals:
Instruction Book for Model TCS-5
Electronic Radio - Television Institute - Omaha, Nebraska
Unites States Marine Corps.
Radio Material School
Undated, with drawing dates August 1941 thru early 1942
84 pages
Instruction Book for Model TCS-12
U.S. Navy Department, Bureau of Ships
By Collins Radio Company
Contact Nxsr-LL-36727
Contract Dated 6 Sept. 1943
203 pages
Instruction Book for Notes on Servicing Radio and Sound Equipment
Electronic Radio - Television Institute - Omaha, Nebraska
Unites States Marine Corps.
Radio Material School
Undated
Instruction Book for Model TCS-12
No. 455 1875
Including Addenda
U.S. Navy Department, Bureau of Ships
By Collins Radio Company
Contact Nxsr-LL-36727 thru NXsr-47395
Contract Dated 6 September 1943 thru 18 January 1944
Includes Installation Instructions - TCS Noise Limiter Adapter Unit (NAVSHIPS 900,005-1B) and Addenda No. 1 on the 20309 power unit and 211330 power unit.
Instruction Book for Model TCS-14
U.S. Navy Department, Bureau of Ships
By Air King Products Co., Inc.
Contact Nxsr-38314
Contract Dated Sept. 23, 1943