I mistakenly thought we might be at the point where I could select one of the tracks and use some automated procedure to match the second tape-drifted track magically into alignment. Alas, we are not yet there as a species.

I did manage to locate on eBay the exact same model of Tascam Portastudio that I used to record with, so I'm hopeful it is fully functional and I will work from there, having found the Easy Button.

Thanks for your input!