Funny, you're thinking of switching from Manual to Power, and I've long thought about switching from Power to Manual!
IMOH AMC's are over-assisted for power steering... Way too soft and mushy for me, but YMMV...
In any event, I've got a '69 Power steering pump, which may need a rebuild, and is missing the reservoir cover, but is yours for the asking... It's from a four speed AMX, so has the double pulley (for the air pump).