FS : IBM Magnetic cards for IBM selectric "compocarte" (?)

The magcard selectric was capable of a lot of basic word processing functions as could the MT/ST before it.? One function it was really useful for was creating personalized form letters. The body of the letter could be stored and personalizations filled in as it printed.? The MT/ST and magcard also had a model with a composer version of the selectric connected.? The composer version had an escapement mechanism that could do proportional spacing, this mechanism was complicated and from what OP technician told me tricky to adjust, and it didn't help that customer using composers where very picky about the print quality as composers where often use to prepare copy for printing.? I have also seen selectric mechanisms that used a lead screw to move the print head which would be an easier way to implement proportional spacing. Watching a video of an electronic composer typing suggests it may have used this mechanism as the carriage motion looks smoother that what you get with an escapement rack. ?? There was also a version of magcard machine that had a IBM Executive type bar typewriter attached, the Executive also did proportional spacing. There was also a selectric called the "Memory Typewriter" that could store documents on a wide loop of tape the was inside a slightly enlarged selectic.? The last version of the magcard machines where equipped with a daisy wheel printer in place of a selectric.