Hey Kevin,
Well, I did a little checking last night. And when I say a little, I mean a little.... Apparently, senior management has been doing a little cleaning up, and most of my old stomp boxes have gone to Good Will. Those that I still have, have been boxed up and stacked in the garage among a myriad of knick knacks and basic clutter.
Ah well, that's cool, but I could only run a test with my Mesa V-Twin foot pedal tube pre-amp(thank God I still have it). It worked well both through the effects loop and when running it directly from guitar to V-Twin to amp... Now that being said, the V-Twin has different lines out:guitar amp,mixing board, and headphones, so it's probably not a fair test.
Sorry that I can't be of more help. Although I sure had a blast kicking it with that V-Twin last night. Man, I love my Skylark. Did you get a chance to do any trim pot adjustments?