There is a circumstantial case for these being renumbered from ACL 14100-14199, class O-22 built 1941, and/or 14200-14499, class O-24 built 1941. ACL 14000-14099, class O-19, built 1938 may be included, though it has slightly different dimensions. Perhaps someone knowledgable about the ACL can verify this?
The dimensions in the 10-1963 ORER are exactly the same for the MRS and ACL series matching no other car series.
Same Superior doors.
Same side sheet and side sheet rivet pattern.
Same ladders
They differ from the builder photo of #14199 in having a strongly reinforced side sill between the bolsters that looks to me, at least, as a later refurbishment. Other 50-6 cars with Dreadnaught 4-5 ends with W corner posts and double doors have different interior dimensions, side sheet/rivet patterns, door types, roofs, side sills, etc.
I appreciate these "out of bounds" photos when they turn up because I have found them to occasionally supplement a meager photo record for series built earlier in the century when railfan photographers were not so numerous. Thanks for alerting us to it, Tim. Eric Lombard Homewood, IL
