>
> >>> import op25
> >>>
>
> I got the prompt right back, no error message.
Right - pretty much as expected. This strongly suggests that the python code you're attempting to use (in this case, from gr-baz) has not yet been forward-ported so as to be compatible with the new GR version 3.7.x API's (and with the new op25 version which has been converted to be compatible with the same). The amount of effort to make it compatible is a total unknown at this point (assuming the tiny patch to the import statements isn't sufficient, that is); Balint would know for certain...
Anyway, to summarize, the test that you ran (above) indicates that the GR-3.7.x-compatible version of op25 is in fact installed (just not in the way that gr-baz is looking for it)...
Max