I was looking for a new loco to weather and came across a prototype of a B23-7 SCL that was patched for CSX. Ebay just happened to have a SCL up for auction which I fortunately won and did pretty much what the prototype looked like except for the numbering and with just a bit of weathering for this one.
I was wondering the same and looked at my slides. Most Family Lines units didn't escape SBD sublettering, but the 7091 [as I found it at Montgomery, AL in 04/1985] had its SCL expertly painted over and nothing applied in its place. With the exception seen here and another similar overpaint on a BQ23-7, all of the Family Lines units I shot from about 1984 forward had SBD sublettering below the cab window.