Chain Locker
I am 3/4 through a major refit of my 38 Salamanda. I have the chain locker on the floor between the pipe cots and windlass just forward of the hatch on the deck.

I have not seen a similar arrangement on any other 38.

Is there a technique for stopping the chain rubbing on the deck when anchoring.

Use a chain grip from Wichard and connect it with a stretching rope to a clamp. In fact this is good seamanship. On bigger Swan's you need it to protect the anchorwinch from heavy loads in swel.

It is assumed you are concerned about the chain chafing on the deck, as this will ruin the surface. For protecting the deck you should put a chain gutter under the exposed length of chain. It can simply be a removable wooden plank with a suitable groove, expect it to suffer with the time. UV-resistant thermoplastic would last longer.
It is a good idea also on this size of yacht to use a chain hook, windlasses are not made to hold big loads. There are different solutions available, on a strop or bolted to the deck, and it is important that the attachment is sufficiently strong and chafe resistant.
Kind regards
Lars

Many thanks, we call this a "Snub" in England. and as you rightly say it is good seamanship.