Hi Fellas,
These Webers were not only fitted to Fiat 124s, but also to most of the large 60s sedans. I have a 1965 1800b (1.8ltr 6cyl) which has a 28-36 DCD 2. The 28-36 DCD 3 was fitted to 2300s, can't readily identify the differences now . They may also have been fitted to the 4 cylinder 1500s.
The code refers to the 28mm primary and 36mm secondary throats.
I have detailed drawings of these carbs, complete tune-up info and may be able to help you locate one/two if need be.
If you need some help, send me a pm.
cheers
John