Advice Needed

[Ole Blue 68]

Ok, here's the problem. I bought my '68 a few months back from what I thought was a reputable seller. One of the reasons I bought it was because it was advertised that it had a rebuilt 283. Upon inspection, it was ultra clean and ran great so I had every reason to believe that this was the case. Now less than 1,000 miles later, the dang thing is springing leaks on me: valve covers (fixed), oil pan and/or rear main seal, and now I noticed a small amount coming from one of the cylinder heads.

So here's where I need advice:

1) Is it possible that this guy really didn't bone me and that something is causing these leaks?

2) How hard would it be to fix these myself? I do oil changes/brakes and stuff like that but never anything this difficult.