I have a Mauretania barrel and one with 'from the wooden walls of old England' on it. I would like to contact some of your members to get some background information. I inherited them from my uncle who was a compass adjuster for Dobbie McKinnis and Clyde.
I too have a small barrel which was made from the deckwood of the Mauretania. There were many of these souvenir items produced when the ship was scrapped in 1935. Several were made by the Hughes Bolckow Shipbreaking Co. of Blyth, Newcastle-upon-Tyne (this firm produced many souvenirs from her teak deckwood, such as garden chairs),and items will have a metal plaque which states that they were made from the teakwood of the Mauretania by the Hughes Bolckow Shipbreaking Co, Blyth, Northumberland. Many of the barrels have a gilt plaque which simply states "From the decking of the Mauretania the Old Lady of the Atlantic". There is no maker's name, however, they were probably made by Thomas Ward Ltd, the shipbreakers which scrapped the Olympic, also, they may have been made by retired seamen. What does the small metal plaque on your barrel state?
You will find more about Mauretania scrap souvenirs on ET by going to the "Other Ships and Shipwrecks" topic on the message board, then "Cunard" > "Mauretania".
As for your barrel "from the wooden walls of old England", I'll happily admit this is something I know very little about, however, I guess that it sounds like the item could be made from the wood of a wooden English warship, maybe from around Nelson's time (early 19th century?) I recall reading many years ago that England's naval fleet, when comprised of wooden ships (before the advent of iron and steel vessels), was referred to as "the Wooden Walls of England".
Hope this is of some help, others on ET may also have more information.