Hi Steve,
Stevenson screens are the way to go given their use in BOM weather stations.
I've noticed how BOM temperature readings rapidly change with time which reflects the superior air flow characteristics.
Your screen may not have weathered well but I'm sure it was a damn side less expensive than purchasing one.
http://www.ebay.com.au/itm/like/3321...pid=107&chn=ps
What a rip off for a plastic box with slits in it.
Steven