There were 2 cast pumps, one with Ford on both sides of the foot [ mid '20's] & another with only one Ford script [ late '20's to early '28]. Probably made by Walker, but a stamped steel pump was also current, much cheaper to make. Perhaps the meatier cast pumps were for TT truck issue?. There are a few photos on the 'net of them eg. MAFCA & MTFCA Forum sites.