Inspector3711 and the walking scale
Try a piece of 3/4" pine for a base. Drill the holes (shallow pits, really) as you were thinking, then grab a few silicone sticky pads from Home Depot to put on the pine board. Use 3 if the loading bench is irregular, otherwise 4 if it's reasonable flat. This way, you can put the scale where you want it. Make the board long enough to have the Beam and Digital on the same board if you want them close together for dumping loads.
"Figure Out What You Believe and STAND YOUR GROUND!"
Nemo Me Impune Lacessit
Lots of Cast Iron to Cook With...
and a few defensive firearms, too!