hi there
This topic of anchor winches has been covered a couple of times on this forum - so a good search may just pay dividends. I know somewhere on here there is a chap who built a winch mechanism which allowed the anchor to freefall to its depth and then be winched back in under power.
I, myself, have built a couple of winches for hauling the anchor in and out; one for HMS Leeds Castle and one for HMS Lindisfarne.
I use an electronic switch which I purchased from Ebay, it gives me forward, stop and reverse. That was for HMS Lindisfarne.
I used an old Electronize 2way switcher for HMS Leeds Castle. This unit was non latching and worked, not from a switch, but from the handset - the up and down lever.
Couple of things to remember - build a slipping clutch into the drive to your winch - so, if you inadvertently haul the anchor too far into the boat, it will slip when it reaches the stop - rather than destroying your winch. The other thing is when your anchor chain/rope is fully paid out - paint or put a big marker on the end of your chain so you can physically see it from the shore when your model is on the water. This will help you know when to stop paying out the chain and it also prevents the chain being wound back in without you knowing.
Couple of links and pictures may help you.
If you look at HMS Lindisfarne you will just see the anchor chain hanging from her side. This is done deliberately to stop me pulling the winch out of the deck.
There is also a link to the unit on Ebay - it is not exactly the same as the one I used, it is similar though - if I can find the link to the one I used I will add that link,.
Sadly, Electronize are not in production now. You may be able to pick up a switcher 2nd hand.
1CH 2 Way Relay Switch Module Electronic Switch Controller for RC Car Aircraft | eBayANCHORS AWAY (modelboatmayhem.co.uk)John