I have both a Speed which has seen much better days, and a Crown, I replaced the Wollensake 135mm with a Zeiss 135 that matched the cam, I broke the rangefinder on the speed so usually shoot with a 150mm or 210 with the ground glass back. I've been thinking about upgrading the ground glass, need to find a supplier and buy cut to size. Also thinking about stripping the leather covering and turning the speed into a tropical camera, but have broken the wooden frame when I dropped it hiking a slot canyon, the leather or leatheate might be only thing holding it together.