It appears they are offering three different car numbers for the same model. The car numbers, however, span two different production lots:
P&LE 20000 - 20999, Lot 800-B, built 11-12-50 by DSI.
P&LE 21000 - 21999, Lot 816-B, built 3-4-51 by DSI.
The two lots were built only a few months apart and were more or less the same, although specialties like hand brakes, etc., may have varied.
As to paint scheme, we do not have any photos of cars that show the exact scheme. This is not an as-built scheme. All the photos we have of the cars with the "Serves the Steel Centers" slogan have the oval from the 1955-59 period, not the cigar band. (As an aside, the cigar band with body color in the background rather than white was not called for in standards laid forth by the parent company. It appears to be something that individual shops did on an ad hoc basis, more so by P&LE, but also by some other system shops here and there. We don't think DSI in East Rochester ever varied from the full black-white-red cigar band.)
Bottom line: these models seems to be very close if not completely prototypical.