I might have a chance to buy a silverface Champ Amp. I have only seen a pictures of it, and it looks pretty rough. I am not an electronics guy, and so I won’t be able to look and see if it is totally original. I am going to try and bring a guitar to test it, but that might not be possible since its a yard sale. It looks like it might have a replacement speaker and power cord. There is also what looks like a crusty transformer? What would you folks recommend as a maximum offer without much more info than these pictures? Thanks for any advice you can offer as far as value.