This thread hasn't seen any action in a while so here you go.
Area 419 talked about a suite of Arca accessories for the press that hasn't materialized. The one accessory they do make doesn't work with the wrenches I have on the press stand. After combing through various photography accessory company's catalogs this is what I came up with for an adjustable tray. The SAC comparators are only there for the picture, a box of 6mm bullets fits perfect too.