People do collect Plumb tools, particularly the earlier Fayette R. Plumb ones, and the Anchor logo ones. I would not say they are super high value, but a lot of users prefer the Plumb axes and hatchets. The Plumb Boy Scout hatchets are always good sellers.
This thread reminds me of the adage that people will collect anything. I have met cribbage board collectors (one guy had over 600), and heard of chastity belt and vintage condom collectors among other things. My wife has a collection of wildlife skulls, bones, and other critter parts she has found in the woods.