Advice sought: Ritchey Timberwolf frame bottle cage mount repair

[d_douglas]

I am looking at a very cool Ritchey Timberwolf frame for my son, and it has one red flag (a fairly good sized one).

The original owner had a set of water bottle cage bolts on the underside of the downtube installed. He said he was told it was done by a local framebuilder, but (IMO) they foolishly never touched up that area, and now it looks pretty damned ugly and a bit scary.

If there a reason to fear buying this? If I were to buy it, what would I look out for? (bubbling in the paint, formation of rust around rivets, etc)?

If I were to buy it (it is cheap), what would I do to protect the frame from future damage? sanding, priming, painting?