and to that end I recently acquired a DEC VT52 decscope terminal which can be seen at left in the picture above. I believe the terminal in this picture is a VT50 as it lacks the keypad, and notes tray.

This photo album shows some of the stages I went through with the terminal, from arrival, disassembly, cleaning, re-assembly, re-wiring the 20mA current loop interface, testing and adjustment

So far the terminal appears to be fully functional. At some stage in its 35+ year life it had been re-assembled incorrectly and 2 of the 4 the twist-lock-pins which hold the upper and lower shells together have broken off. I've only cleaned the outer plastic lightly, mostly with water and soft toothbrush to avoid subjecting the old plastic to too much assault, so it retains multiple decades of grime embedded in the textured finish of the plastic shell. There are residue of sticky tape and pen marks scattered around the front-face of the terminal.