I joined the Empire club! Found this 398 in its original box with original paperwork at a garage sale. I have the MAAS polish out and I'm about 1/3 of the way through this thread. Feeling impatient and decided to post.
It is cleaning up nicely. The issue I have is I'm only getting sound out of one channel. I have yet to clean the contacts on the cartridge. Sled pins look OK to me. RCA cables seem to be fine. I fear it may be a wire on or within the tonearm, which I believe is not an easy fix. It looks like the sled wires may have been re-soldered at some point. I also notice that the tonearm seems a little loose on the base. Hopefully some cleaning will sort it out.