OK, this makes more sense now: Alfa's 9-digit numbering notation in the 1950s (introduced with the 1900 series, I believe) was in the format of aaaa.bbbbb, of which the first 4 digits often were the product (or supplier) group. In some parts catalogs, the same numbers were shown in aaaa.bb.ccc notation, and in others (as in your case) without delimiting periods. In rare cases, there can be a slash "/" with an additional digit added, indicating a part variation in a 10-digit format. In 1958, Alfa introduced a 12 digit numbering system with the 101 Giulietta and 102 (2000) series of cars, with a numbering scheme of aaa.bb.cc.ddd.ee/ff where the first 3 digits usually was the vehicle series the part was introduced with and some parts received 2 more digits after a slash (making it a 14-digit number) when evolutionary variants were introduced.
The writing on your tag seems to indicate 1413.62714 or 1413.52714 (the crease makes it difficult to see if the number is a 5 or a 6), which would date the part to the 1950s.
The 1900 series used one 1413.38 number (grille heart) a few 1413.80 numbers (dome light, flasher unit, etc -- all of them being Carello components), and two 1413.90 numbers (lens gaskets for lights). The Giulietta series used about half a dozen of 1413.80 numbers (for internal and external lighting and flasher unit) and one 1413.90.145 number (a gasket for a side indicator lens) -- again, all of them seeming to be Carello components. The cross-reference section of the 102 parts catalog lists no 1413 components, so this model series can be ruled out.
So, unfortunately, due to limited exposure, I think there will be little help from people knowing passenger cars. I would suggest you contact Tony Stevens at AlfaStop in the UK
, who knows Romeo vans, Mille trucks and Romeo 2 ambulances quite well and may be able to look up the part for you.
It would be interesting to learn what the deal with the "Brunsig" patent is.