Something must have been enticing M-type owners to take photogtraphs of their M with more people in and on it than just the two it was designed to hold. I always enjoyed the photos of the two gentlemen and two ladies (in what appears to be bathing suits) and of the five uniformed men. The third picture was recently posted on the facebook page of the MG Octagon Car Club. The original poster discovered the photo on the Morecambe web site. Although the quality of the photo is not too good and it is hard to see any detail of the M itself, the (nick) names of the people may be known to some on this forum.
July 1929 was very early for a car for "Wrecker Longley" to drive!! The first cars having build dates of late March in time for the Lands End trial, with production starting in late April. So that by the 2 July they were up to 2M0436, so it must be earlier that that car! The MG number looks to be the original, but is not recorded by Julian Evers in his list.
Could that be a faded question mark after 'Morecambe'? If it is, perhaps the writing was added to the picture when memory began to fade. Note the door hinge position. My guess is the photo was taken in 1930 or 1931.