OP
If the amp lasted 16 years it doesn’t owe you much at this point. You could put a lot of money into it and then something else that is currently working and therefore not going to be fixed at this point might go bad soon. I would make the 30 minute drive, pick it up, and sell it on eBay for parts, hope to recoup some of what you already spent, and then use the rest of the projected repair cost on a newer piece. IMO, there hasn’t been that much development (except for the rise of Class D Amps) in amplification technology over the last few decades, and (this is personal, ymmv) MF amps were more known for grunt rather than finesse). Change can be good