A pair of GC's (12 cell series) will swallow 90 amperes. So will paralleled 27's or 31's.
My firearm days are long gone. Last week I was within 700 miles of Sebastopol. It isn't likely I'll be getting back there. If the guy who owns the house found it he likely sold it for drugs. I had a rental of his and he isn't the most stable person around. That H&H is a side by side weapon and lifting it was like holding up an axle of a 3/4 ton pickup.
Anyway returning to sanity --- A pair of those 600 watt boosters paralleled offers decent charging voltage without involving the need to taser the converter thermistor.