Oddball 135/4 Hektor

[Greyscale]

I have a 135/4 Hektor lens in M mount. However, the serial # on the lens head dates the lens from 1951, which predates the M mount by several years. Also, it lacks the groove to attach the IUFOO lens hood, and takes 36mm push on hood instead. So, either this is an LTM Hektor which has been converted to M mount, or a pre-M lens head in an M mount lens body, if this is even possible. Which is more likely? The focus scale on the lens body goes to 300 feet, if this is helpful.

 

[Kate-the-Great]

I think I've read that Leica offered factory LTM -> M conversions in the late 1950's and early 1960's for new M users that had screwmount lenses and didn't want to futz with adapters. Could be that?

 

[Greyscale]

That could be. I think maybe the original user wanted to keep this 135 because he could use the lens head on a Visoflex, and wanted to be able to use the lens on his (now my) M4. The more you dig into Leica/Leitz, the more you realize that you don't know.