[Arran]

Hello, Marv: I just happen to be working on a 37-660 right now, which is very similar to your 665.

NOTE that in addition to the two 8mFd electrolytics located near the power transformer, you also have a small electrolytic can on the RF deck that houses 1, 2, and 3mFd caps. I strongly recommend you replace these, as all 3 are in contact with B+.

In order to replace the can and the paper caps in/on the RF deck you will have to remove the deck to get at them. This is not a simple task. Make sure you diagram and mark the wires as you de-solder them.

Since the small electrolytic can is located in the hard to access RF deck it may be an idea to substitute poly film caps for the small electrolytics so they don't have to be dealt with again, if you have the room or can stuff them inside the can.
Regards
Arran