Honestly, I'm not completely sure what the issue is since I haven't been in to see it myself yet and I can't get ahold of a service manual to see what this particular piece looks like.
[Quick summary: need advice/more info so I don't potentially get screwed by my technician]
I'm kind of in a tough spot given a lack of available information and experience with servicing VHS units-- which is why I decided to appeal to you fine folks here. My concern with the whole thing is whether the tech is making the issue seem bigger than it is-- especially in light of some possible "red flags".
First, when I bring the unit in for service he's surprised to see it since he used to be a mitsubishi servicer and hadn't seen a U-80 in person ever as they were higher-end and not too common. I call him for an update a few weeks later, he's not sure (I say no rush), it's then done the next day. I get it home to check it out but it's eating tapes right from the start. I bring it back since work was guaranteed and this tension band brake problem is found.
He said he couldn't find a replacement part after calling the company and a few other places; he does mention that he has a functional mitsubishi unit in the shop but isn't going to pull it out of there-- which I understand, no problem. He then offers to "trade" me a different functional mitsubishi unit he has in the shop (I think an HS-U51, which is not SVHS). At this point, I reply that I'll have to get back with him as "I may have a friend that either has a parts-unit or may want to buy mine for a parts unit" and that I'll get back to him once I find out, he says ok.
As it appears to me-- the writing is on the wall with regard to the tech: get me to agree to a "swap", he takes the part from another mitsubishi unit in the shop, and *viola* upgrades to a functional HS-U80. Obviously, I'm not thrilled about that deal on my end. So, my only other option is to figure out a way to fix the part as you've proposed or find another unit to get a functional part from.
Sorry for the long version-- but thanks again in advance for anyone's advice or help!