Zenith carb float help

I have a Limbach SL-1700 EA1 aircraft engine (1700 cc VW). It is in a
Scheibe SF-28A.

The carburetor is a Zenith 28 ZXF and the float is defective (plastic). The
Limbach factory has not sold parts for this carb for 25 years.

Need a new float. Would love a rebuild kit, also. With the unfavorable
exchange for the Euro, and all the necessary parts to change to the Zenith
150 CD carb, the cost is about $2,200 (an ouch here for emphasis) - all
because of a bad float.

Any ideas? The Aero-Carb looks like an option, although that would take
some modifications, and I would rather be flying than building.

Thanks, Colin