Jeanne,
I have a little bit more information for you. I felt around the windlass box on my E38 and there is a backing plate. It must be plywood, probably 3/4' or maybe an inch thick. It's about 8 or 10 inches square. That's not much of a mod, the teak box is more expensive than that.
I talked to the owner with the vertical windlass that is in the middle of the bow locker door (see my previous post) and he said he wouldn't necessarily do it that way again. He found that the door's balsa core had thoroughly rotted - unexpected extra work cleaning out and filling. He said he would install a horizontal model rather than the vertical, and he would position it so that the rode would drop right down the pipe into the locker. That would require some interesting structural work up there, to the door and the pan underneath.
My first experience with the vertical windlass in my boat was just this morning, in calm winds and in barely enough water to keep the keel out of the mud. I found out, as I wound in the chain, that the chain can override on the windlass (the gypsy?) and I ended up jamming the chain before I realized what happened. I have no reverse on my windlass, so I ended up driving the boat over the anchor to free it and then motored to deeper water before freeing the override and manually pulling the anchor in the rest of the way. Once the anchor was out of the mud, I easily freed it from the windlass.
I wonder if the two empty screws in the forward part of the windlass base are used to attach some kind of block that prevents the chain from overriding?
Good luck what ever you do. I guess they're back savers, but I have some learning curve to climb!
Craig