Hi all, I found a used Ampeg B50R at a local store with asking price of $250. I really like its tone but its potential issues due to its condition is a concern to me. The pots all work, but the volume pot is quite scratchy. I am not sure if it can be fixed with contact cleaner or not. There are what look to be dried liquid stains (or what looks to be hard-water stain) on the surface that could be wiped off. The stains, which are pretty big, are running down on left side and back of the amp on a couple of places I assume that means someone some time ago spilled something on the amp and didn't clean it off. But what really concerns me is that the transformer that's exposed on the back of the amp is completely covered with fine red rust. The transformer being completely covered in rust makes me to think that this amp has not been stored/maintained properly. What do you think? Given its condition, especially concerning the rust-covered transformer, would you consider buying this? So basically, I am asking, "should I pull the trigger on it?" FYI. If I am to get this, I will have to sacrifice my Acoustic 260 MKII mini-stack, which is really good amp except it is little lacking in high-end and bit muddy. Thanks for your input.