If you get them tested for parameters I'm sure there will be several of us that will run models for them just to see what they can do. I've found a few articles on the web about them, a couple said thay had a hollow sound to them, and a few more that said they had some extremely deep pleasing tones even at very low volumes playing orchestral music. It would be quite interesting to find someone using still putting them to use in this decade.
One quick question. Are the ones you have paper laminated on the front of the cone, or just the bare high density polystyrene foam? It turns out theres actually three different iterations of this woofer, on is pure paper, one is paper laminated, and the other is bare psf, and it seems that the pure paper has a lower fs, but laminated version sounded better even with the higher fs because of the better cone dampening.
I'm sure tls will chime in with his opinion on this too.
Good luck!!!