Surviving Shipwreck Memorabelia - Aerogramme and the Ebay auction house discovery

This has just come up after a Lochiel google search. An aerogramme from Port Charlotte, Isle of Islay addressed to New Zealand that was on the 8th October ferry run when the ship went down. The aerogramme was recovered and marked up 'Damaged by salt water - Recovered from ss Lochiel sank 8/10/60'.
Auction house Spink ha put the item up for sale for over $500 dollars - a couple of bids were place for a mere $280 (wow!) - so it doesn't look like it went under the hammer. The auction item reads:

'Description:

Maritime Wreck Covers of the World

Europe

1960 (8 Oct.) M.V. "Lochiel", struck the Torraturch rocks, finally grounded 600 yards from her destination, the West Tarbert Pier in Escart Bay, West Loch Tarbert, Argyllshire, 6d. aerogramme from Port Charlotte, Isle of Islay to New Zealand marked on reverse "Damaged by salt water. Recovered from S.S. 'Locheil' Sunk 8/10/60" in red ink and with strip of Found Open or Damaged and Officially Sealed tape. Photo'

I thought this was fascinating - the fact it survived and these artifacts appear to be of interest (and high value). My daughter looked at me rather blankly when I showed her this discovery!