Hello guys!

Just wondering If you could help me out on my most recent purchase. I've acquired a kwk43 shell and upon cleaning noticed someone has painted the shell head with hammerite black paint! I've very carefully removed the most i can but noticed there was a red number 5 followed by some other small piece of red paint. My question is in the photo I've posted the it reads ohn 11.5.43f on the head. What does this mean and could mine potentially read 11.5.45f? I ask this as after the 5 there is reKwk43d paint that goes straight up in a line under a magnifying glass potentially being a capital F as in 45F. I think I'm at the end of the writing and not the 5 in the middle of ohn 11.5.43f.

Many thanks