Hi Mike;
I think you are describing a 'PCB card edge connector' - I am not sure there was a specific 'GPIB' edge connector, they were just the generic edge connector.
What pitch are the pins? - most PCB card edge connectors were 0.1" - 2.54mm, some were 0.15" - 3.96mm.
How many ways (pins) do you require? [From memory, GPIB uses a 24 pin Centronics connector]'
Most edge connectors were double sided. Back in the day I used lots of them in various products I worked on.
I think I may have a few odd edge connectors in my junk box.
Regards
Jim - G0LHZ