> my PYTHON_PATCH_SCRIPTS doesn't make any change on
> the python shell scripts

Didn't look deeper, but I suspect this is due to the
NO_CONFIGURE=   yes
line.
The "replace-interpreter" target in bsd.pkg.mk is part
of the CONFIGURE_PREREQ list of targets. With no
"configure" happening, it might be skipped.

If this is true, it would be a good idea to fix bsd.pkg.mk.
For now, a dummy "do-configure" target in your Makefile
might work as a workaround.

best regards
Matthias