Sure looks like the case of the Lexington "B" from this 1958 ad used in OldTicker's example.
Note thequad dial in the ad, as seen in OldTicker's example.
Looks like the Lexington "B" was available as early as Spring 1955 (Model list below)
Same model/variant still available in Fall 1958 model price lists, w/ same unique model number (below).
So there's two Lexington "B"s with diff unique Bulova model numbers (same for Lexington A). Could the price diff btwn the two "B"s listed reflect a different mount and perhaps a black dial? Who knows?
Subject watch could be a Lexington "B" with a repained black dial vs the white quad dial shown in the ad, or it could be that Lexington "B" was also available in a black dial version (31107 $57.50) for which we don't have an ad. There is evidence that two were available, but the distinction remains Unknown.
For now, I would give three ticks for generic Lexington (no variant) and two ticks for Lexington "B" noting that it may or may not have come Point Of Sale in a black dial version.