Can you upload photos? I usually opt for back removal over top removal, unless top replacement is in order.
Here are a few pictures of the damage. The bellying behind the bridge stands 1/8" above the surrounding flat of the top, and that's without string tension. The top has the large wavy wrinkling-type warping off the back corners of the bridge as well. In the interior mirror shot, you can make out the extra plate wood, as well as two dark chunks that were glued on top of it at the rear outer edge. Quite a sight, to be sure!
I like Eric would take the back off because you can then dampen the inside of the top and put a good size piece of plywood on the inside as well as the out side and clamp it good and tite. Leave it for two days in a warm room. But first remove the bridge and bridge plate. Then you can repair any braceing or any other repairs that needs fixing as well as making sure you don't have to replace any braces. You may find that you will have to take or replace the tone braceing they may have been bent to far out of shape by now.And if it needs a neck reset it is very simple to do that when you go to put the back on again.Good luck with your repairs Bill.............
That top is shot. I don't really see what you could do to rectify the situation short of top-replacement. Do you really want to be yet another repair guy associated with this guitar's complicated repair history?
If that guitar showed up in my shop, I would refer that customer to a guy like Pat Diburro or the martin factory for a top replacement.
I find myself both in agreement and disagreement with Nathan, I disagree that the top needs to be replaces. I agree with referring it to someone else. That is some NASTY repair work. I know my limitations for stuff like this. I would ship it on down the line, lest two years from now, he is bringing it to someone else and mentioning your name. Just my opinion though...
Dave don't let the name on the head piece intimidate you if you think you are up to the task go for it. If you think it needs a new top then put a top on it you have the guitar in hand you should know best Bill............
It looks like it's ready for bridge plate #3, and bridge #? I've repaired many such situations that looked equally bad, and it's quite amazing what you can get the top to do once the plate and bridge are off. That being said, judging by the other repair work, I'd say chances are good the gluing surfaces under the bridge and plate have been turned into hamburger already. There is a finite number of bridges and bridge plates that can be put on and taken off before you run out of spruce. You can laminate if necessary, but you're already at the limit of what is practical and worthwhile for a 73. I'd bet it needs a neck set and a refret as well. And there's probably a pickguard crack. Retopping will cost even more and make the guitar worth even less. Are you sure he wouldn't be interested in a nice new Santa Cruz or something made before 1968?
If you can replace the bridge plate and reglue or replace the bridge it may flatten right out. I've had worse looking tops turn out great. Once you get the bridge plate off dry clamping a new one will give you some idea of how much the top will flatten out.
I'm not a luthier and I don't play one on TV, but Frank Ford has some good articles on replacing torn out spruce under lifted bridges in www.frets.com. Worth a look before deciding what to do. Look at some of his major restoration articles. The cost/benefit ratio might be tough, however.