There are no superficial cures to the problems your engine are suffering. What you are in need of is professional help, seek out a good machine shop and provide them with an itemized list of the history of the engine. Take the car in and show them first hand what the problem is and ask their advice and an estimate for a cost to cure. If they feel it is just a head problem, then you can remove the heads and have them do the work that's required. If its rings (too) then you can punch out the pistons annd re-ring the engine with their specifications.
The secret is finding someone that you can trust and has the ability to do the work, and explain the reason why its required. Good luck on your endeavours.