Hi,
I cannot help with a 325 install but can refer you to my post of 4yrs ago when I fitted a lewmar electric winch to our 27. This necessitated constructing and fitting a second chain locker directly below the original and cutting a hole between the two which the chain could drop vertically.
I also mounted the vertical axis winch on a peninsular so the originla cqr could still be fitted in the top locker. The locker door had a small dome fitted in the middle over the winch so the door could shut.
The pictures are still available under the Parker 27/275 section
This was one of the b est mods done - we now anchor and recover with ease and havnt used a marina since!
best of luck
Chris