Well this obviously started life as either an Austin or Morris Mini. You can't tell which, as, unlike the cars, the van and utility (or pick-up) versions had the same grille, the only difference being the badging and the badge has been removed from this car. It will be a UK built example as the Australian built ones had the same grille as the passenger cars rather than this one. Given the sliding windows, it would also be a fairly early example.
I suppose the puzzle is either who did it, or what has been done to it, and that I haven't been able to figure that out yet.