Perhaps unsurprisingly proxying type-related methods doesn't work.
I think it's possible to get this to work but it may require some new and inventive use of the new method first.

from padme import proxy
class my_int(proxy(int)):
   pass

Currently it is somewhat hard to implement a proxy that is both stateful (as it in can have internal state) and transparent (so that the state is invisible on the outside and doesn't clash with the original).

I'll fix this in a moment (I actually already have so I cannot even paste the error) but tests used to fail with more recent version of mock. The _mocks attribute we access is now mock.mock._mocks. I'll fix this in a moment.

To be fully feature complete, it would be nice to implement the host of various numeric dunder methods, such as __add__ and friends. The complete list can be displayed by pydoc3 SPECIALMETHODS

Currently the code is written in pure python 3.x+ but with a few tricks it should be possible to support python 2.7 as well.