HELP! I bought a mess?

Might not even need to pull the engine if its the valve seals. Don't know which freeze plug or if its accessible but there are replacement freeze plugs that are rubber with a screw tightener that you can put in with the engine installed.
Unfortunately the suspected culprit of the antifreeze leak is the freeze plug on the back of the block on the passengers side under the automatic transmission bell housing. That's ok. While I have it out it will get cleaned up, all new gaskets, the correct paint job after losing those hideous chrome valve covers, and either some the original cast iron manifolds that came with the car or some new shorty headers.