DEC VAX/VXT2000 and monitors

Hi all, Trying to clean up the "inbound" queue of systems-to-check-and-fix, and here's a few boxes I cant seem to figure out. Heeeelp ! ;-) Basically, the monitor madness I guess. I have: - various VAXstation 3100-family systems with mono, GPX and SPX cards - various VXT2000 boxes with their SPX card - a VXT2000+ box with "SPX PLUS" card and, two monitors (only.. gave the rest away long time ago.), a VR19-D3 (seems to be a generic GDM1960 - it also has the HI-LO switch on the back) and a VRT320. The VRT320 is the one that actually seems to work on all the GPX cards, and on the SPX cards in the VXT2000's. It does NOT sync with the SPX cards in the -M38 and -M76's, and neither for the SPX PLUS card in the VXT2000+. Obviously, I would want the -M38 and -M76's SPX cards to be used, and the SPX PLUS in the VXT2000+. No specs on the latter can be found, though, although I did notice that there is a 74.3MHz xtal on it, rather than the 69.9 one on the regular card, so it might be doing the 1280x1024@74 rather than @70. Does anyone have info on this? Cheers, Fred