A full rebuild may require things like throttle bushings/bearings, power valves, and other hard-to-get parts. A typical cheap-o rebuild "kit" will probably have a few gaskets, o-rings and needle valve. However, I'm not too familiar with flat-top rebuilds so someone who's done it would be more informative. The 32/36 DGV is a "progressive" carb. The 32 is the main venturi diameter and 36 is the secondary venturi diameter, in mm. The DGV feeds the engine with the 32mm venturi until enough demand opens up the 36. They are also downdraft carbs, not desirable in an inline engine configuration. I'd prefer a good set of flat-tops to DGVs, hands down.