My experience is tgat selling “specialty” items is much better accomplished when appealing
to the proper audience.
I dont know who that is in the case if such large items, but perhaps there is a publication
for those who Build or Maintain large physical structures like bridges, or work on
behemoth construction vehicles?
^THIS^
Thought maybe someone here might know place where people described above look for used tools such as this on the regular.
I’m on that forum as well, never sold anything there but I know people do regularly sell tools without much issue! Proto is well loved over there, and I’m sure you’ll see some interest.
BAM!!! 
There it is!! Thankee much 