Hello tipo160,
Your engine number "makes sense" for a car with chassis 915003. We do not have a lot of truly meaningful comparative data from the earliest 6C2500 examples, so "makes sense" (at this time) might not be truly comforting in the future?
I have finally dug carefully through some files and found some material that may help you continue your study of 915003. I've made some scans of various materials, some of which are likely copyrighted. I use them as study tools but will not share them here. In the end, if you wish to learn who made the body, I think you will want to remove a number of trim items and search for a body number. I do not know of a numbering system for Boneschi, but it is likely they had one. We know that Touring had a numbering system and the numbers are generally not difficult to find in a body that is mostly original … and which has many of its original trim parts. Sometimes you will find only the last two digits of a four digit number. The number may be stamped, scratched, painted or crayoned/penciled on some parts?
I am attaching an image I found that I'd copied during the late 1980's (perhaps early 1990's?) in a museum in Italy that is now called something different but which is still a very fine museum with an extensive library. Cross-referencing the image from1939 (most likely) and that time period to a Boneschi ledger reference in the "Boneschi" book of 1989 by Sergio Puttini, I see an intriguing possibility. On 28 December 1938, an unidentified Alfa Romeo "6C2500" arrived at Boneschi and a "cabriolet 4 posti" is listed with the client being "Alfa Romeo". Of course, it might be that the car was a 6C2300B instead, but I am wondering ...
You have seen the image of a similar body shown at Coachbhuild.com? I only just saw it a couple of days ago.
Semmartin, please remember that Tito Anselmi's published listing is derived only in part from Alfa Romeo records. The Registro 6C2500 notes are based in large part on Tito's listings and then other information has been added as it is found. Alfa Romeo records do not exist for chassis 915003 and we have only observations and studies to go by when we report about a great many of the other early 6C2500 cars. Most of the cars described on pages 288 and 289 are described with information sourced from outside of Alfa Romeo records. I am inclined to think that Tito also arrived at a similar tentative conclusion about 915003, perhaps based on his own studies of the same material I have found, but it is possible he had some sort of proof? If so, that proof probably did not come from Alfa Romeo.
Again, I believe it will be most effective to look for a body number in the car itself (found in several places) so as to identify the car as Touring … or perhaps Boneschi. Either way, it should be one of the only cases where we can document a 6C2500 chassis that was perhaps completed 1938? I am also attaching a worksheet that may be used to describe other aspects of the car, some very easily found and documented as you search for the body number and identity.
Best of luck!
John