DarrinD,
If you don't think you are going to have room to put new hinges in you can leave the current ones in place. You can leave them there ONLY if they are in good shape. Look at them, if they are damaged or weak then you have to replace them. But for the sake of this let's assume they are in good shape, and your only problem is that you don't have room for new hinges. So here's what you can do. Strip off the old covering and leave the control surface hinged. Then when you recover the plane start off with sealing the hinge gap with covering. In fact, I do this on all of my planes. It seals the gap which gives you better performance from the plane anyway. Plus, with CA hinges it gives you insurance against a hinge failure. Basically you'll have 2 types of hinges on the plane, the CA hinge and a covering material hinge. You will never have a hinge failure this way.

Anyway, quick explanation of what to do. First of all cut yourself a strip of covering. You'll have to cut it wide enough to fill the gap with about 1/8"-1/4" extending out each side of the gap (usually 3/4"-1" is wide enough depending on the plane). Then fold the strip in halve (with the adhesive side out). It's easier to apply this if the control surface is fully deflected away from you so the gap is open, I use masking tape to hold the control surface away from you. Remove the backing from the strip of covering and then put the strip into the gap, with the fold line directly on the hinges in the gap. I usually use a trim iron for this because the small head is easier to work with, but you can use a regular covering iron if you're careful. Starting on one side of the gap seal down the covering to one side of the gap, all along the length of the control surface. Then go back and do the other side of the gap. Then on one side of the gap fold down the excess and seal it to the wood. Then go do the other side the same way. Now you can recover the plane as you would normally do, just bring you covering right up to the edge of the gap.

See pictures for an example of what I'm talking about

Hope this helps

Ken