Have to let you know about this site....they sell "Queen Mary" teak deck chairs....that have never been on the Queen Mary...that is their style.http://www.twenga.co.uk/search.php?q=queen+mary
of course it is in the UK but feel you need to all that is out there for reference. They sell pretty good.
I personally nor anyone on this site can vouch that these are in fact authentic....it is one of those items that has to have a hands on....however, the brass hinges are a biggie that was needed on all joints due to salt water exposure....(the brass joints you have are a big plus). Can only keep looking....find photos of the Queen Mary with some like these on deck to truly identify.
It could be that someone bought them for novelty from the Queen Mary, painted and tagged them...which will still make them very novel and a nostalgic collection piece.
I'll keep looking!