I know this is a long shot being the board were made somewhere around 1988, but I am willing to purchase any 488-PC1A cards that anyone has in inventory. These cards are made by ICS for the ISA slot and use a very specific memory range.
This is Eduardo, I am an Applications Engineer for National Instruments.
You are correct as we don't have this cards available for sale but let's check if there is a user of the forum that has a used one for you.
Thank you for that excellent resource, however they do not currently have the 488-PC1A card listed. Unfortunately the software we are required to use was specifically written for the PC1A.