You might try contacting B&C about this: firstname.lastname@example.org
... and let us know if they answer you (and what that answer is) because I have a similar situation. I have a couple of B&C neo drivers taken from 808 cabs and sold to me for $150 apiece because the owner is convinced that neo is crap. I've got them in cabs untuned to the drivers at present that I use for non-critical gigs (sound OK) but would like to build these cabs for them too if it's a fit.
FWIW I built a couple of B&C cab designs for a pair of their 21s (21SW152s) and the results are awesome! These are very solid designs.
And very solid drivers.