I have finally found several photos of a "drop-in" arrangement for putting a sewing machine in a portable base into a recess on the top of both treadle and non-treadle table/cabinets. However, I've also managed to come up with another thing to ponder about: my portable base has two holes for the treadle belt, but most if not all of the photos I've seen of similar bases have a slot instead of individual holes. That would certainly make it much easier to switch from portable to a table. In my configuration I would have to disconnect the staple joint on the belt each time I moved the sewing machine.