One of the MAFCA restorer series of restoration books has dimensions for them. They are a specific size of steel strap and only have the one short leg bend right up front but a person needs the dimensions for location on the floor, length, bend location, and bend angle to make it easier. There may be more than one variation but I'd have to find the Restorer info to be sure. The AAs have that two speed rocker shift mechanism so they might be a little different.
I'm not sure is the early types are long enough but someone else may know. They may only be as long as the lower floor section. Maybe a short piece could be welded on. It might be easier to just bend some locally purchased steel strap. I would check all the sources of parts first if you haven't already. Someone may have old originals or new ones.