Since you provided such a clear explanation of what you do and don't know, it is a pleasure to help
It is R965 and C965.
R965 is 10ohm 5% 0.25W
C965 2.2uF 20V tant bead on a 15V rail; I would prefer that to be 25V, and the capacitance is not critical. If that's faulty then I would think of replacing similar caps, provided you can do that without damaging the board.
That's in one of my 475 manuals that is stored on my machine with the name "tektronix-475A-dec84-SCOPE-INS-14678.pdf"; it may have been a different filename when I found it.
There are several different types of tantalum, some extremely reliable, some less so. Epoxy tant beads are less reliable, especially when operated near their rated voltage (Tek 485s have 15V caps on a 13V rail, doh!)
(And that's my post 2
12 )