Gtk version screwup?

I have a 2023 installed wxpython - wx.version() -> gtk2 (classic) under ubuntu installed with apt.
A much older, circa 2017, installation wx.version() -> gtk2 (classic) under fedora with dnf, Both run under python2.7

I have been tearing my hair trying to understand problems in my very large wx application. I have just noticed the gtk2 vs gtk3 above, which seem the wrong way around! I think the gtk3 binding is much less buggy than the gtk2.

The gtk2 version is on a i7 and the gtk3 on a pentium d. Obviously I would like the gtk3 version on the higher spec machine.

I have 3 versions of python. 2.7 obviously, 3.5 with broken pip, and 3.7 and pip which seems to work.

I tried: pip3 install wxpython but got the following after the wheel churning 4 cpu(s)100% for 6 minutes:

Command '"/usr/local/bin/python3.7" /tmp/pip-install-hk1gf9o5/wxpython_e6170559c3c94f82973b1682f268fa1b/bin/waf-2.0.24 --wx_config=/tmp/pip-install-hk1gf9o5/wxpython_e6170559c3c94f82973b1682f268fa1b/build/wxbld/gtk3/wx-config --gtk3 --python="/usr/local/bin/python3.7" --out=build/waf/3.7/gtk3 configure build ’ failed with exit code 1.
Finished command: build_py (0.739s)
Finished command: build (0m1.272s)
Command ‘"/usr/local/bin/python3.7" -u build’ failed with exit code 1.
[end of output]

note: This error originates from a subprocess, and is likely not a problem with pip.
error: legacy-install-failure

× Encountered error while trying to install package.
╰─> wxpython

note: This is an issue with the package mentioned above, not pip.
hint: See above for output from the failure.

~ o ~

The question is how to do the install without getting into version hell?