Hello:
The actual bumper bracket (that bolts to the cars frame and accepts the bumper bars) is the same on the A400 as some other Model "A" body types. The model that a particular bumper bracket fits is determined by the height and position of the stand off bracket (sometimes called a "T" bracket) that is rivited to the bumper arm. In the case of the A400, the "T" bracket is 3 1/2" tall and is rivited approximately 14 3/4" from the large bend in the bumper bracket. If you care to provide your e-mail address or a FAX number I'll send you a diagram.
A400 Guy
Art,
On YOUR car, one of the rear bumper brackets was replaced. It is the one with the stand recessed into the wooden crossmember. The other should be original. If my memory serves me, the one bracket was actually broken off. I searched through swap meets for one matching the existing bracket, found one of the same length, but found the stand was slightly different. So, I recessed it into the crossmember.
Phil
I know it is a feature of most 1931 cars to have the rounded ends but my A-400 rear brackets are not rounded and I am pretty sure they are original.
Larry