DWalt - Found an expired listing on Guns International for a Bpt. Bulldog ser#193621. Link below
Charter Arms Bulldog - 44 Special - Early Bridgeport Gun

Also found one in the National Museum Of American History that numbers at #271371. It was provided by the FBI for display. Maybe "Son of Sam's" gun?
Charter Arms Co Bulldog Revolver | National Museum of American History

I had a Stratford made Bulldog back in the early 1980's when I was a serious backpacker. Lot of juice in a small package.

Larry