Nice progress and a good find on those cabinets! Have you considered putting a wood top on them (like you made for your new bench) and use them as additional bench space?
Also, concerning that caliper bolt - if you ever run into that issue again, its not a big chore to shorten a bolt, all you need is a hacksaw, a file, and a couple of nuts. First, you thread two nuts onto the bolt. Then you unthread the outside nut to the desired length, and use the inside nut as a jam nut to hold it in place. Double check your measurement before cutting. Then, put the assembly into a vise and cut it to length using the hacksaw, using the outside nut as a guide. Next, use a file to flatten the face of the bolt so that it is flush with the face of the outside nut. Then, unthread both nuts from the bolt - when you unthread the nuts, you will actually fix any damaged threads. Use the file to add a chamfer if needed. Finally, thread the nut back on/off to make sure there are no damaged threads.
Even though I have an angle grinder, I still usually use the hacksaw and file more often than not. On small bolts, it takes about the same amount of time to just cut and file it as it would to drag out the grinder, switch wheels, find my face shield, etc. On larger bolts, I've found that they usually get too hot to handle and you end up having to wait around for them to cool before you can assemble, so the job ends up taking just as long either way.