Reviving a barn found engine

OK, so I pulled my spare engine out of my garage, and it was much uglier than I remembered. Lots of oxidized aluminum, very dirty, and rust on every fastener. Wow, it sure looked better in my head!



So, I started cleaning it up, dropped the radiator and drained the coolant (only a little was left in there), and got my first hint that this was going to be... different. I bought the engine around the same time as the bike, so I didn't know much of anything about our bikes at the time.



I went to open the radiator drain plug, but there wasn't one. Just a smear of epoxy or something like that. Like I said, first clue. I continued to clean up, pulled the valve covers (one has a hairline crack that was patched with RTV sealant, second clue) and spark plugs. I then turned the engine over a few times-- first good news, not seized!



Next up I was going to adjust the cam chain tension, but take a look at the picture-- what is missing there, instead only a smear of epoxy/goo? My cam chain tensioner bolt!





So, OK, what do I do now? The engine on my bike had some sort of full fledged coolant/oil combination due to my stupidity. Should I resign myself to cracking both of these open and hope I have enough for a good bike? Or just adjust the valves on this thing, install and take a listen? Why would someone do this???



Or look for another engine? There's a bike for sale with a hundred miles for $120, but I should not really be spending that right now. I'm at the too many projects stage right now, with twin 17 year old daughters cars being a 1078 Volvo and 1974 Bug, both of which have many needs. I just want to be able to ride!