Manual transaxle shift cable replacement?

You have a somewhat rare car these days. It was an Isuzu Impulse that GM rebadged under Geo. The catch is that Isuzu redesigned the platform in 1990 and stopped production at the end of 1992 with just a bit over 10,000 made. As such the parts for those are likely not available. On the Geo side they stopped their production at the same time but still produced some parts to cover warranty. The problem is that once the warranty was up, most of the parts get sent to other places or scrapped. However, being this is just two push pull cables it should be possible to make a replacement using the cables from a different vehicle because they were likely an off the shelf part. I would probably start by looking in salvage yards. If you go to Car-Part.com and enter in the information on the car then select transmission, you might find yards that still have them in the vehicle with intact shift cables. Then you just call them about buying the cable assembly.
For instance, https://morganhighway.com/ shows what is in the second image. They might have the rest of that assembly.
Beyond that you would be looking at adapting cables from a different vehicle.