The MS-6205 came out in different versions (looking at schematics it was probably dependent on IC availability), but the external electrical interface was kept the same and the neon matrix lamps used were very similar.

The model that I have consists of (going in order from the neon matrix):

• Cathode Driver PCB - glued to the lamp with epoxy, contains cathode driving NPN transistor ICs, the lamp wires are soldered to the PCB.
• Anode Driver PCB - permanently attached to the Cathode Driver PCB with flex ribbons on 2 sides (no easy way to flip open), contains anode driving circuitry and cathode selection logic
• Logic PCB - connected with separate wires on one side to the Anode Driver PCB, has the high voltage generator (12V to 240V) and all the logic needed to store pages of text written to the display and turn them into pixels (page RAM, character ROM, clock generators, page selection logic etc.) and obviously the big 2 row connector.

For people who don't have connector labels: if you orient the display so that the side with the connector is facing you and the neon matrix is facing down (see zoomed in connector corner photo). Then row A is the bottom one, row B (Б) is the top one. The pins are numbered starting with 1 on the right and ending with 32 on the left. If your connector has a group of 3 pins, then a gap, you should count the gaps too so that it all adds up to 32. Be aware that in your version of the display the connector can be rotated 180°, row A is always the one with the widening notches.

To complete my project It should be enough to replace the Logic PCB (maybe except for the high voltage generator) and start controlling the pixels while skipping the character page/character ROM logic completely.