Seems you have an extra number there. I show it to be a Zenith #12303 (model 261-😎 carb.
The repair kit is a Zenith #K2061A
The float is a Zenith # C85-116
Both available at http://www.russellsnewoldparts.com/CARBURETORKITS.html
or kit only at http://www.ase-supply.com/