I'd have to see it but many times you can just buy as big of a connector as you can, aka 24 position ones and then just cut/dremel off to a size you need.

Measure it to see which it is.
0.1" -- you get ten pins in one inch.
0.156" -- you get seven pins in one inch.

For 0.1" plugs --
Molex 22-01-2197 (obsolete)
Generic CS100-19-LR
https://www.greatplainselectronics.com/proddetail.asp?prod=CS100-19-LR

For 0.156" plugs --
Molex 09-50-8191 (obsolete)
Molex 09-50-3191
Generic CS156-19-LR
https://www.greatplainselectronics.com/proddetail.asp?prod=CS156-19-LR

I take it you're talking about the J2 display connector at the 6803 MPU board.
It's a 0.100" connector.
If you're wanting to replace the pin header, the singular pins are pressed into undersized holes in the board. The pins are very difficult to remove without ripping the through hole vias/pads out.

Could be cracked solder joints on the J2 PC mounted pins. Inspect them first.
Re-pinning contacts within the plugs can also be the fix. Try that second.

Quench brought up a very good point. This series of boards used press fit header pins on the PC boards which make these a real bugger to replace. As long as they pins look good, leave them alone (except for inspecting for cracked solder joints). Don't replace the PC mount pins unless you really need to.