KK, I love your bench. I'd like to build something similar. Can you take a pic that shows the whole bench?
Here's the set up on one wall of the 32' building I load in.
This is the beginning pour for the concrete top of the 12' loading bench.
This is the final look of the concrete top. The legs are bolted through the floor with lag bolts. I use 2"X6" boards clamped to mount to the top. Two presses are on a converted grinder stand and they pivot to present the one I want to use. The other press, Hornady LNL AP, is set up on my old loading bench made of 2"X6" boards.
I used concrete for the top hoping I could get stability for my Mettler scale, but it still isn't stable enough. If I had it to do over, I would use something other than concrete.