Hi Mick,
Here’s a couple of pics with the measurements in mm taken from the table edges, pics are not too good but should give you an idea.
I’m convinced the mounting plate needs to be moved over and back towards the edge of table.
I’m also having difficulty fixing to the rear door as my water carrier assembly is too far towards the door 😳 However it does fit in the over sized wardrobe I made, so I may secure it in there.
On another note I briefly saw Justin’s 101 fire truck the other day, it looks really good and will certainly be a rare sight over here.