HI,
The EZ 42 was a gyroscopic gunsight that was slated to be used in the Me262, Fw190, and Me109. Apparantly it was also slated for the Do335 (though I have found no evidence of that).
It was first produced in 1944 and installed in the FW190 with JG6. it was also installed in the me109. Unfortunately very few were made. I have photos of it used in a Fw190 and Me262, and also some origial parts that have setting for the Me109.
It basically had settings for various aircraft inlcluding the mustang, beaufighter, halifax, lancaster, boeing, spitfire, hurricane, thoundrbolt, lihgtening and librator. Once the pilot identifued the target, he would reference enter the correct number that corresponds with the aircraft he was attacking. Using a vast array of gyrosropes and power supplies, the gunsight would automatically adjust the depending on aircraft speed, angle of attack etc.