Trying out the following to possibly buy from a local pro. Both he and I typically play the Paris-Selmer Chorus 80j for jazz. Love that horn. Wanted something for a bit more projection and brilliance because of certain reasons. Already communicated with John at Calicchio. S/N is 1847 Leadpipe says "4" stamped near the receiver. A "4" is not listed in current Calicchio specs from what I have seen. Maybe a compromise between a "3" and a "5" (?). Bell says 3L. I know the 3 and I think the L just meant Large..or larger than a standard 3. Bottom of valve case is stamped M1 It is rose brass and has no 3rd valve finger loop on top of the slide. I understand this was a prototype (?) that was made by Dominic (?). Looks like this could be around 1963. A prototype of what? Blows pretty freely and is quite bright but first impressions as far as depth and richness of tone were not great. Playing a slightly bigger MPC (Reeves custom) helps that but not much. But what it lacked in tone it made up in ease of range. Any knowledge of this? John says very little data on these early horns but he is going to check into it.