Ok so my old brain was being dumb. Using a hit and miss procedure I found gpio 23 is actually pin 16(pin I chose in your script).
I couldn't get it to run on startup/reboot so I added sudo python /home/pi/reboot.py & just before the last line in /etc/rc.local. Works like a champ.
A thought crossed my mind, crontab didn't work for me because I actually wrote a new file. Should have: sudo nano /etc/crontab -e to edit the actual file.
Thanks for your help. I was determined to find a way to prove your script works since obviously you've been at this longer than I.
Treat me like a really young student or dense old geezer and I shall learn well