Cam bearings aren't put under the same loads as rod and main bearings so they aren't as critical to have perfect, they basically just hold the cam in place, plus the cam only turns half the speed of the crankshaft so that's maximum 3000-3500 RPM depending on how high you rev the engine. They're also a pain to install and oftentimes need some massaging so that the camshaft can rotate freely. I had new cam bearings put in a 360 block but when I went to install the cam it wouldn't seat all the way and was very hard to turn, I had to take the block back to the machine shop and they fixed it up (for free).
There's one cam bearing in my 5.9L block that looks kinda like that but not quite as bad, probably just gonna leave it. Looking at your engine I'm much more concerned by the RTV on the head gaskets and the nasty leftover oil, I don't think it was run at all after the "rebuild" hence the empty oil filter which is probably a good thing, it would have torn itself up pretty quickly.
