Lots of great ideas, but for this season, as long as it's not going too far for too long and you keep an eye on oil levels, you will probably be OK. Setting aside the cash for a complete rebuild is a good idea because no one knows what they will find when they get in there.
You might get lucky and just need a replacement head gasket and seals, but if head is off, may as well cut the seats and no one is going to re-fit cracked chain guides in a professional rebuild and if it needs a cam chain and the motor comes out and so it goes on. Hope for the best and be prepared for the worst.
With any luck the head will still be flat and all it will need is a top end re-fresh. But who knows, maybe a port job and a re-profiled cam and big bore high comp pistons are in its future...........