Trevs-
By all means use the batteries for a test pack as is. Once you have proof-of-concept, you might be able to bring them back for awhile with a Desulfator. If you can't find one at a good price, here's one you can build:
Desulfator for 12V Car Batteries, in an Altoids Tin
Later(after they die for good), you might want to try converting them to Alkaline-rinse out all the acid with Distilled water, add a mixture of distilled water and Alum (about 10+grams to the gallon) and start conditioning them with light charging cycles until you get the Voltage back. With any luck, you'll get a rechargeable battery that will safely discharge well below 80% and no longer sulfates-and if not, you can still recycle them...