Gave it a look....no difference. I've changed out the needle, thinking it was to small for the polyester t70. Removed the feed dog and inspected it for burs (it's pretty worn, will replace) and have gone through the adjustment possibilities with the tensioning discs (minor grooves...will also replace) I have noticed a light, the only way I can describe it is, an inconsistent "popping" sound in reverse. Like the needle/thread is penetrating differently, maybe pulling up on the fabric differently in reverse.(I am sewing through a laminate sail material so the needle penetration does often make some sound, but this is different in reverse). I did just replace the bobbin case with a more inexpensive alternative, but it looks like its good quality. It is of the variety that has a disc to keep the bobbin from spinning needlessly in the bobbin case. I guess that could also be a factor?
I sure appreciate your help, thank you!
Greg