You might want to read some posts by greatlaker221. He is refitting a Hershine 37 and had similar issues. When he removed the teak, he found a lot of rotten wood behind it. See his blog: Saving Tortuga: Walls and Windows OMG!
The way I look at it is that when you have a 30+ year old boat there is bound to be some patina and other wear & tear. Your damaged areas are relatively large compared to the few I have beneath portholes, but I would be trying some stain were I in your situation and then a satin varnish of your choice over the whole lot. If you dilute the stain and apply multiple coats you might be able to blend it in with the undamaged area. You wont get it perfect but you should be able to make it less obvious.
If by the end of the satin varnish stage you think it looks like crap you can then paint - the last resort as RTF says. You lose nothing by giving some stain your best shot.
But if the veneer has lifted and wrinkled - which does not seem to be the case - then you might need to replace the veneer.
A problem of refinishing is applying finish to only the affected areas. With antique furniture it is usually a full strip and refinish, purists hate losing the original "polish". Delaminated areas are toast.I have some stained areas that are in good shape except for the staining. I realize the veneer is so thin its almost impossible to strip and refinish it, but I'm wondering if something like Minwax varnish that has stain in it may be able to be applied in one or more coats to blend the stained areas with the unstained ones. This would not be difficult and is something I'm probably going to try at some point. Conversely, I have a couple of areas that are seriously delaminated. For those, I think removal is the only viable option.
Ken
A problem of refinishing is applying finish to only the affected areas. With antique furniture it is usually a full strip and refinish, purists hate losing the original "polish". Delaminated areas are toast.
I recently had some interior ply and veneer replaced, it worked out better than I expected. You need an accurate pattern to cut the new panels so they slot in perfectly.