The 70mm ones went down one side of the film, then things were flipped around and they went back along the other side.
Hi John, I've worked quite a lot with long-roll portrait cameras and never heard of such a thing. I wonder if you've misunderstood the term "split-70." This was not actually split down the middle; rather, the frames were shot sideways on the film. So a split-70 frame was ~70mm TALL, whereas a full-70 frame was ~70mm WIDE.
The main long-roll portrait cameras for sale in the US were Photo Control's Camerz line, and Beattie-Coleman's Portronic line (I never heard of Keith Camera, so couldn't say). Both were available in full-70, and probably any other version you wanted. On top of that, there's been plenty of custom-made equipment specific to certain companies, but much of this is virtually unknown outside of those companies.
Back on the main topic, I have no idea who would use non-perf Delta 3200, except perhaps, as David suggests, someone with a surveillance system. It seems most likely that it would be some sort of legacy system that isn't worth upgrading. On the other hand, if it's a single customer, there's not much point in B&H listing the product; the actual customer would already have all the ordering info. So who can say, aside from B&H and the customer?