12mm BULLDOG Pinfire Revolver

This 12mm Pinfire 5 shot revolver looks like the .44 centre-fire.
It is stamped BULL-DOG on the top of the barrel and has no proof marks.
Looks Belgian and only numbered 45 on the trigger and 4 on cylinder front.

150mm long with a 64mm barrel. Cheap but unusual looking pinfire firearm.

Yeah this one is a little unique. It’s probably early 1900s too. Are there proofs?

As stated , there are no visible proof marks.