I thought about cutting my Peavey 215 BW cab to make (2) 1X15 cabs. The problem is that flakely, particularly board crap that the cabs are made out off. It weighs a sh!t ton, doesn't take screws well, and doesn't tolerate mositure well.
I put a pair of Eminence Deltalite II 2515s in and a metal cup with Speakons. Weighs MUCH less, sounds 300% better, and handles a lot more power.
IHMO, the old drivers aren't worth saving neither is the cab.
The Delta Lite II 2515 (really all the Delta Lite IIs) is an excellent driver. Can't hang with the very best, but just a notch down. And not 100% sure, but likely at least as good as whatever is used in the very top-of-the-line commercially available cabs.
Tremendous bang for the buck.