[R-390] R391 Audio Deck Question

[g4gjl at btopenworld.com]

Im investigating why my R391 has gone dead, so I pulled out the audio / power deck...

 In looking around I noticed one of the liquid / acid tantalums decoupling the cathode of V603 (6AK6). I need to replace this cap as it has all but disintegrated (obviously this is not the fault Im looking for, just colateral observation) however I cant find reference to this cap in the R391 manual.

This is a Collins manufactured deck bearing dated components no later than 1955. It is COL serial No 203, FWIW.


Was this cap a later addition? Is it part of MOD2 by any chance? The deck is stamped thus.

Comments appreciated, chaps, and by the way Happy New Year to you all.

Pete
G4GJL