Art,
Here is the reply I just got from GO in reference to the two blue dial PML's and what the difference is. I wonder why they would make two versions?
Tom
Regarding the grinding, unfortunately we do not have photos on which it is visible and could be compared. However, we can try to explain it as follows:
Reference 1-90-02-24-02-04 has a plain dial.
Reference 1-90-02-05-02-04 has the mentioned grinding. It is a curved, radial decoration. When the watch is orbited against incident light, the light reflected by the ground surface moves around in a circle.
We hope this is more understandable now and remain at your disposal for further questions.
Kind regards
Your Glashütte Original Team