Request for help troubleshooting AA5 radio

[maxhifi]

Mid 60s GE radio, bone stock AA5, all on one horizontal PC board. Nothing sexy about it, but it's used daily and I want it to work properly. So far: replaced filter capacitors. Replaced 12BE6 and 50C5 due to excessive H-K leakage. Peaked the two screws on the tuning cap with an RF generator and scope . Did not adjust IF transformers due to not owning a plastic hex key.
Radio is now sensitive, hum mostly gone, IM hum completely gone with new 12BE6. Remaining problem is audible IM distortion on complex music. It's not in the audio section, and doesn't vary with volume. Talk radio or simple music sounds fine Any ideas? Alignment? Silver ,ica disease? Note this radio has all ceramic disc caps except the filters which are brand new