Recovery Option #2: The DIY Solution at the link I gave above is quite similar to what Fro posted.

Charging Your AGM Battery
Tech Tips – Powered by OPTIMA® Batteries
Tech Tip #3 – Don't Throw Away Your "Dead" AGM Battery: Three Tips on Resuscitating a Deeply Discharged AGM Battery

Use a 6v battery charger and an additional, good, fully charged 6v battery.

Tim
1954Advance-Design.com
1954 3106 Carryall Suburban
1954 3104 5-window pickup w/Hydra-Matic
The 216 and early 235 engines are not "splash oilers" -- this is a splash oiler.