That is a gorgeous machine and cabinet and I think you got a great deal for $125!!!
I would not worry about the warping and discoloration of the cabinet. It's so minor and I do not think it detracts in any way. If it REALLY bothers you and it is solid wood, then a light sanding and staining to match would solve the problem. If it is veneer or you do not want to tackle it yourself, then take it to someone who refinishes furniture and they should be able to repair it for you. In my opinion, I would leave it it--an antique machine does not need to be in a cabinet that looks brand new!!