Found an old, broken tool inspection device (looks like this one: https://perfectionindustrial.auctionserver.net/m/lot-details/index/catalog/162/lot/30801/) that seems like a great candidate for some linear rails, steel shafts, and linear bearings.

Here it is after some disassembly. I have to figure out how to get the shafts out of the base still.

Close of up the carriage assembly. Need to work on tearing that apart further.

Close up of the linear bearings. Have to do some research to get those out without damaging them.

Picture of the vertical slide. There is a matching one on the carriage, and these will be used on the Z-axis to keep it square.

Still have to find pillow blocks, screws, and more bearings and shafts for the Y-axis, but it is coming along nicely. I have a lead on an old plotter that I may be able to get a screw and maybe some pillow blocks.