I think that the closest BBb to this tuba that you are likely to find is the new, one piece, King 2341. I have a side by side photo of my King and a York EEb identical to Carl's, and they look almost identical.
Here's the photo of the York next to the King. The main differences, other than overall shorter tubing, appears to be the 4th valve tubing wrap, the angle of the valves, and the main tuning slide.
