This is already getting WAY over-engineered...
KISS is head to a Harbor Freight or other like store. Buy a brass airline QD. I use these on both my Co2 tanks With no problems. After a year 1 now has a slow leak in it and needs replaced, So I will have to spend $5... You will also need hose barbs. (Oddly I was headed to that store today for a non-related project so thanks for the reminder!) The other QD is still fine.
“I'm not drunk, I'm from Wisconsin.”
We have been out drinking your state since 1848!