David , yes you can lay down in it , but your legs are sticking up the wall:-D, I got some drawings from the interior , very cramped , if you slide through the door onto your seat at each end , than that is about it .
got frame back from shotblasting today , needs a few holes in the drawbar welded up , didn`t see them before the shot blasting .
will mesure it up , but the dimensions are given in Canada`s fighting vehicles europe 1943 45 . frame is same as mortar trailer and GS .