In general, West German Zeiss did not produce any lenses for the Leica (with the exception of the Hologon) until its recent foray into the M mount.
Any Leica mount lens that you find is most likely either wartime production, East German or a custom adaption of an existing lens.
Regarding this particular lens, this looks like it is in a light alloy (aluminum) mount, which would either make it wartime or East German. Further inspection shows it to be a Carl Zeiss Jena T lens, which means that it is coated and presumably of East German origin.
I can't see the serial number, which would help to provide a date for the lens.
If possible, try to check the collimation of the lens. That is most important when it comes to any Zeiss Jena lens that has been adapted (custom or otherwise) to a Leica mount.
Not taking away from the Sonnar, it's a very good lens, but I don't think you should expect a 50-year-old lens to compare with a modern-day lens costing thousands of dollars, especially when it comes to the "bokeh" conversation.
You will get great photos, and the Sonnar has its own nice characteristics. It's considered by many to be one of the great 50mm lenses of all time. But don't compare it head-to-head with a Summilux, because it's not a Summilux. Regardless, I think you'll be quite pleased with it.