I'm looking at a Belgian guild gun with no maker's name and these proofs:







Couple questions:

Am I correct in concluding that the gun was proven pre-1924 because the chokes are listed as a fraction?

Is 6873 the original proof pressure, or does it refer to something else?

Is 70 a statement of chamber length here?

I can't find the bird/dragon proof on any tables. Do any of you know what it means?

Is there anything else worth knowing that I'm missing here?

Thanks for your help!