Now, let me throw in a suggestion or two and a precaution to boot…
I wouldn't be tempted to “ clean ” the old rubber boot with Armoural for I think it leaves the rubber surface such that your wetsuit cement might not bond to the old rubber very well. I would use a weak solution of dish detergent and work it very carefully with a very soft brush [ if brush at all ] and then make sure all the soap residue is flushed off. A little rubbing alcohol would help you do the final cleanup and carry away the water.

Then let it thoroughly dry before starting with the gluing and special coats of wetsuit cement. Make sure you get the moisture out of the inside of the boot too. A hair dryer might help here. Your idea of using

That special wetsuit cement is not cheap... ~$7 :
http://www.sportsbasement.com/jump.jsp?itemType=PRODUCT&itemID=4570 but neither of these vacuum elements.
I figure $7 worth cement could potentially repair several thou$and dollars of such parts... boots as well as the diaphragms !

Great contribution to the THREAD Bob!
Best regards,
Sam