Replacement display for Tektronix PSU PWS2326 - can you help?

[Mrnt]

I obtained a PWS2326 which unfortunately has a broken VFD and as far as I can tell from Google (and after contacting Tek) replacement VFD's are not available. I have a spare front panel for a Tektronix 4000 series PSU and although the pinout for the connector between the front panel and the main board seems to be the same as the 2326 it does not display anything when plugged into the PWS2326.

The front panel contains a processor which interfaces the keypad and VFD to the main board via 4 logic signals, but when I probed them I couldn't make much sense of how the front panel and main board are communicating. In the event that a replacement VFD is not available I was thinking of removing the VFD and replacing it perhaps with an OLED driven by a microcontroller which passively observes the interaction between the existing processor and main board, displaying whatever is appropriate on the new display.

So two questions:

1) does anyone know of a source for VFD's for this unit - the original appears to be made by BOE model VFD30-1202?
2) has anyone reverse engineering the communication between the front panel and the main board or could give me some pointers as to where to start?