A day after I posted the plans for the Len Morris Mk II scow, pictures were posted on the scow Moth Facebook group of a Mk II that had just come on the market in Australia. This one was built with the flow-thru cockpit; the original design had a tub cockpit, which indicates this particular Mk II could have been built in the early 1950's.
From the bow, the distinctive humpy nose block which gave some structure to the forestay attachment.
A transom view. You can get a good look at the absolutely flat bottom of the Mk II.
The flow-thru, double bottom cockpit was very radical in the dinghy world at the time this Mk II was built. It would be another twenty years before the International Moths started adopting them. (though a historian would say the sailing canoes had them 120 years ago).