Typically "Crown" is said to be B&S. I vaguely remember some much more specific story where a Los Angeles retailer may have used that for a private stencil, but can't dig that up. Can't imagine what strange place this weird little critter might have been born.
The corrosion on that helicon is eery, rusted away like a steel exhaust pipe.
Principal tuba, Bel Air Community Band
Old (early 1900s?) Alexander BBb proto-163
1976 Sonora (B&S 101) 4-rotor BBb
1964 Conn 20J/21J BBb (one body, both bells)
~1904 York 3P BBb Helicon
Old Alex Comp.F, in shop