HQ Sandman was limited edition initially afaik, then they were built to order. By the sheer volume I have recorded I still reckon there were only 100's made, very much like HQ Vacationers. Sandman was a regular production "model" in HJ and there appears to have been heaps of these and HX's too. HZ appears to have been popular early but died off heaps by the end of 1978.