IWC Mark XIs

Hi everyone, would really appreciate it if some one can shed some light on these 2 pieces that I have.

The one on the left is from '51 and the one on the right is from '52

Both pieces have military engravings on their case backs and movements. However, the '52 piece clearly has a period incorrect dial as it's missing the pheon and circle T. Does this mean the dial was replaced at some point in time?

Also, each piece has a diff lume material. The '51 piece has a green paint whereas the '52 piece has a yellow paint on the dial and white paint on the hands. What might these different paints be?

Lastly, I noticed some minute difference in the casing as well. The '51 piece has an extra "step" on the side as compared to the '52 piece. Could this difference be attributed to design revisions between those 2 years?

Thanks in advance!

The dial on the right looks like an early service dial. Pics of the inside and outside case back and the movement would be useful. This article may help you http://gregsteer.net/IWC/Mark_11/IWC_Mark_11_Horological_Journal_2020.pdf

Edit: For what it's worth. my first impression is that the case lacking the small step to the case back has been extensively polished, which has removed the step.

Thank you for the resource! I didn't know there's another paper on this watch out there.

Upon closer inspection, it does appear that the '52 piece was polished. I can see remnant of the small "step" between the lugs. I also noticed that the '51 piece has a more curved domed crystal whereas the '52 piece is more flat. It seems that the '52 piece underwent some serious and thorough restoration at some point.

Here are some additional photos

View attachment 1794086 View attachment 1794087

I love these Models 👍

Can you post al lume-shot with UV?

AFAICS the hands the left one looks "neon"-green -> they might have been relumed (in the (80ies). I own a Bulova mil (relumed that time) and this looks similar.
my2cents