I checked out that post on WUS. That movement is dated to 1930 (omega). The case says only Bulova Quality (and has a serial number which is obstructed in the photos, and it looks like its the first digit that's obstructed). Can't date the case on that one w/o first digit of case SN.
The three B.W.C.Co examples we have on site are all housing 1929 10AN's. The six digit case SN's used can't be used for dating.
It kinda looks like- when we consider the 1930 WUS example- the several 1929 examles we have on site in non-Bulova cases hallmarked BWCCo may have morphed into a model cased by Bulova in 1930. If BWCCo when out of business in 1929, they would not be producing this case in 1930.
We see too many 1929 examples for them to be one-off's IMO. While we don't have a model name for either the 1929 BWCCo or the 1930 Bulova example, I doubt we will ever have a Bulova model name for the 1929 non-Bulova. We just haven't found an ad or documentation naming the 1930 Bulova model- yet.