And having put a test roll through and found the camera to work properly, you can legitimately list it as "film tested" and get a better sale price when you want rid.

I'd keep it. I have a Pentax K2, KXs, and MXs but I still bought a couple of supposedly broken ME bodies recently. Both turned out to be absolutely fine after a clean and new light seals, they may only have aperture priority auto mode but they're solid little things and will produce very acceptable results with careful use of the exposure compensation dial. It's useful to have a camera and lens which you're not too worried about damaging sometimes. I wouldn't take my K2 out to photograph an off-road competition, but an ME with a cheap winder and old zoom I bought for pennies and cleaned...