I picked up a 700/60, the ANSI version of the HP 700-series terminal and when I took it apart to clean, it had a VDC 1401DP31BE inside. I swapped the CRT into a 700/92 which has a slightly different board, and a burned in amber tube, and it worked fine. Also I noticed the 700/96 PCB is almost identical to the 700/60, so I'll try a rom swap to see what happens.
Too bad there aren't generally available cross reference list for terminal CRTs. FWIW, the 700/96 has a Philips M32ECD3G CRT. VDC is having a "sale" on the 1401DP4 and P31. The tube price is pretty cheap but the shipping is about double when you price it against their normal $55 price. The shipping goes down with quantity, so if you buy 5 or so it ends up being about $25 a tube and significantly cheaper than all of the ones listed on eBay.