This will develop into a very informative thread John, many of us Massey Collectors are not serious Cast Iron Seat collectors, we just collect and display what is of interest to us, but I know there are many serious seat collections and collectors worldwide.
My contribution today is a very nice display of Massey related seats I admired in August 2012 in the M-H feature building at The Le Sueur Show in MN.
The three seats are cast iron, I have seen the S572 one before and have one in my own collection, the E293 pictured is the first one I have seen and would presume very rare. Very nice seats amongst the display of many Massey related items.
Malcolm.