I would happily take a chance on a 99 like that. The metal polishes up easily with the right stuff, and it's usually all about cleaning and oiling.
It's very tempting to disasseble the parts holding the bobbin case it place, if you go for this machine, don't do that until you have read the service manual carefully and plan to spend quite some time getting it correctly adjusted again. Removing the screw right infront of the bobbin will make everything slide around there and cause major tension problems until it's adjusted correctly. It's not impossible to do it, but as a first DIY it's not recommended with out a warning. The recommended way (illustrated in the manual) is to slide bobbin cover completely off, then lift the lever up and towards you, and the bobbin case comes out with ease.
From the pictures it looks mostly dirty and it's not difficult to clean it up, it just takes a bit of time. If there's any rust it comes off too.
Last edited by Mickey2; 02-16-2017 at 02:25 PM.