It's whether the bridge is mounted to a "biscuit" or a "spider" that's important here. Dobros had/have spiders and Nationals have/had biscuits. ("Dobro", incidentaly, originates from the Dopyero Brothers who emigrated to the US from Europe and started producing resophonic instruments.)

It has often been said that the only consistent thing about Gibson's musical instrument production is it's inconsistency but I'm pretty sure they never produced a square neck resonator with their name on it. There's no mention of one in Gruhn's guide which is probably the go-to for such matters.

I suspect someone in the past has tried to big it up.