Maybe Steve, but I think we ruled this out. The only casting numbers on the rear end are on the axle housings. I am sure these are part numbers.
Of the "Pitchers" you sent the most similar is the B. Perhaps this pump arrangement is an add on of the homemade variety. The axle housings were originally cast with a bracket top and bottom near the wheel but they have been torched. The wheels are definitely 26 inch. One tire is indeed 13.6. The other is a 14.9.