Thanks Fatalsaint, again! Got the (hashkey not working)! /usr/bin/env python at the beginning assuming the Exec=python /opt/healthcheck/healthcheck.py is for the .desktop file? (replace current line?) (the icon loads, and it looks like the application loads, so not sure the error is there.)
/opt/healthcheck/healthcheck.py *or* cd /opt/healthcheck/ ./healthcheck.py
python /opt/healthcheck/healthcheck.py *or* cd /opt/healthcheck python healthcheck.py *or* Exec=python /opt/healthcheck/healthcheck.py