Food for thought - I have the same windlass and was getting ready to shell out 3 grand for a new one when an idea came to me - why not adapt it? So.... I bought a 1/2 right angle drive electric drill, made a simple adaptor with a piece of stainless bar stock that fits in the handle slot, drilled & tapped for a 5/8 bolt, screwed in the bolt & cut off the excess so as to be flat on the back side - cut off a 1/2 drive socket extension w/15/16 socket, chucked it up in the drill, plugged into inverter and cranked up the anchor. It works perfect AND Millwaukee tools makes a portable, rechargeable drill for about $350 which I will get soon as I dont care to drag extension cord around.
Just a thought - if your 555 sea tiger is in good shape, you can power it up for less than $400 bucks! Good idea????