Very easy and very cheap. Plywood for the sub plates and Tee or Tophat nuts from below set into a line of holes set back from the bench front as I suggested earlier. 3/4 plywood plates with 5/16 screws all 'round to hold the presses to the plates and then bolted through the holes to the Tee nuts set into the holes from below. By using regular increments for the holes you can put anything anywhere on the bench.
As the second picture shows it's not only for reloading presses. The vise more or less lives in that location and I made the plate a bit bigger to better spread out the loads and impacts. But in a blink I can unbolt it along with the presses and have a clean top.
Items other than presses? The machinist's vise obviously. But you can also secure a rifle work stand or make up a simple bolt down foot to hold a work lamp or any number of items. For example the small hobby size drill press you see in the second picture is now mounted to a "box" with a drawer for the drill set and chuck key that bolts to the table through this same set of holes.
I think the Tee nuts were about 80 cents from Home Despot when I bought them. 5/16 nuts fit into 3/8 holes. So it's super cheap, super flexible and super durable. If you want more placement options just put more holes spaced closer together so you can move the items around in "half steps". For your bench I'd suggest the first two be in from the edges about 2 inches and then space the holes on 4 inch centers set 5 inches back from the front. That makes the plates large enough for good load spreading. And it keep the bolts back from the edge that the leverage is to your benefit.
