All the Mac toolbox objects (Windows, Dialogs, Controls, Menus and a zillion more), All the Windows HANDLEs, all the MFC objects (although they might be a bit more difficult), the objects in the X11 and Motif modules, the pyexpat parser object, *dbm objects, dlmodule objects, mpz objects, zlib objects, SGI cl and al objects....
Could you please try once more, being serious this time? AFAICT, I was asking for examples of types that are parsed by means of O& currently, and do so just to get a void** from the python object.
Looking at pyexpat.c, I find a few uses of O&, none related to the pyexpat parser object. In zlibmodule.c, I find not a single mentioning of O&, likewise in dlmodule.c, clmodule.c, almodule.c, dbmmodule.c, and now I'm losing interest into verifying more of your examples.
AFAICT, you are trying to replace O& with something. Where, exactly (specific source file and line number), would you want to do that?