I realize there have been a number of threads about this mark, so I thought I'd start another.
My hope here is that we can put together a definitive reference for folks to figure out what they have. Here are mine:
Clearly Bura due to "LB", but late Bura by size of the mark and the sun indicating an assistant. This blade has "U.B." on the other side.
Also a late Bura, but lacking the LB notation. Has UB.
Slightly earlier Bura. Smaller crescent also facing different direction. Also with sun; UB on flip side.
This one is the questionable one. Appears to be a KLUVK, so likely Keshar Lal using the crescent. No UB notation.
Please add corrections or pics of your Crescent marked blades.

Clearly Bura due to "LB", but late Bura by size of the mark and the sun indicating an assistant. This blade has "U.B." on the other side.

Also a late Bura, but lacking the LB notation. Has UB.

Slightly earlier Bura. Smaller crescent also facing different direction. Also with sun; UB on flip side.

This one is the questionable one. Appears to be a KLUVK, so likely Keshar Lal using the crescent. No UB notation.

Please add corrections or pics of your Crescent marked blades.