Toronto. Willard Morgan’s nifty Sliding Focusing Stage must have been selling well because in 1938 Leitz Wetzlar began to make and market the accessory which by this time had a spring-loaded clamping bar to hold the camera both in the NYC and in the Wetzlar versions.
The Wetzlar stamped accessory was given a new code as well – OOZAB. The OOZAB and the NYC version were both made and sold through 1951 when the NYC accessory was dropped. The OOZAB was modified at that time to an H shaped clamping bar to clear the flash socket of the IIIf.
I picked up my c1955 example from Dave DeShon in September 1978. This version of the Focoslide which used the camera lenses was made through 1957.