I've had one of Westminster Forges canteens for over 20 years and I've been in Tom Browns shop where he makes them. They are not recommended for alcoholic or high acid (cider) liquids. They are not tinned and are soldered with food safe non lead material.
I have a fairly full set of his camp pots (2 gallon thru 1 pint and a 5 gallon cistern) all hand made by one craftsman- Tom B.
PS Dave I like the strap and sleeve.
Kevin