Rayfield model N.
This carburetor was sold as a price leader under a number of different names including Johnson and Marvel-Schebler through the various discount mail order auto parts stores. Borg-Warner had purchased several of the lesser carburetor companies, and marketed products through each companies previous avenues.
Good luck on finding any parts. If you really must use this unit, would suggest fabricating what you require. However, if you wish to look, there is probably an identification number STAMPED on the airhorn in the format 10-nnnn where nnnn is a four digit number. While the design is Rayfield, the numbering will be Marvel-Schebler.
Jon.
