Attached is a link to my mates online library of Pest Control papers. Here is a "Fuller traps catalogue" from the early 1970's. Scroll down and you'll see The Legg Multi Catch Trap. Think it was designed primarily for squirrel, but was probably good for rats too. Scroll down further and you will see The Fuller Multi Catch Vermin Trap. Think this maybe the one I seen years ago.
http://pest-contol-papers.boards.net/thread/91/fuller-traps-catalogue-early-1970s
As I already mentioned, i've never used a multi catch myself, so can't really recomend anything, but I'm sure there are similar t