My apologies to those who have already thought of this, but when I was the sailing master of the Humber Keel, Comrade, we often had to lower the 67ft mast and ship it on deck. To help in getting this huge lump of timber for'ard we had a wooden roller that sat in the mast tabernacle (it's called a lutchet on a Humber Keel ). As I unship the mast on Falcon and support it just clear of the cabin top, when I leave her at the club I thought a similar arrangement would be useful - and preserve her varnish a little. I found this handy little rubber roller. Just 90mm long and with an 11mm bore it'll fit perfectly on the mast bolt.
http://www.pstrailers.co.uk/epages/BT4713.sf/en_GB/?ObjectPath=/Shops/BT4713/Products/BR2101
Delivery was very quick indeed and reasonable I thought at just 3 quid.
Steve (wot's full of miscellaneous facts - like the mast hounds are called oynings on a keel )