Cicerogue - after applying a small amount of denatured alcohol to the back of the cabinets, I am almost 100% certain the finish is shellac. The finish came right off with almost no rubbing required.
I have tried a variety of applications and don't really like how any came out. I used some stain pens but the issue is the area I need to cover is too wide. If it were just a scratch, no problem, but trying to match a 1/4" wide section is just too noticeable, almost draws your eye more towards the blemish. Quite frankly, I think the original blemish looks better than trying to hide it with some easy fix, so I have removed the stain pen repair at this point.
I may try to just shellac the lighter area but also think that the outcome will be similar to my results above. Need to think if I want to remove the shellac from the entire top of the cabinet. However, if after re-shellacing, and if the color doesn't match the rest of the cabinet, I just signed my self up for refinishing not just the remaining cabinet but the other speaker cabinet as well. Ugh! Best course of action may be to just live with it for a while to see how distracting the blemish is.