Cat; here are a couple under-the-plate shots of my '81 Distillate. Not sure if they will be helpful to you, but so far as I know, the board has not been altered. The bass had its 4-position switch exchanged for a pan pot before I got it, but that shouldn't matter here. I also added a ferrite bead bead around the pickup leads.
Good luck sorting out your trouble... ain't much better than an old Distillate. Love mine.