Markson

This is the New Zealand Markson.

The present owner bought it believing it to be a Bolwell. Bryan C, of Melbourne understands that they were built on a Mark 5 chassis. The sills look like the Mark 5 as do the front hinging bonnet pivots. Does anybody know any more about the Markson? I've tried Googling Markson and and the best I could come up with was someone wanting the stretch MARKS ON his penis explained.