Fuchs wheels with no number in raised box

[RI 3.2]

I have an 87 3.2 that came with 15" Fuchs when I bought it a few years ago. I recently replaced the 15s with Braid 17s. I listed the wheels on ebay with lots of pics except the actual part numbers. Those I just stated in the listing. An interested party asked the question. "Do the part numbers end in 41 and 42 or 11 and 12?" All part numbers are correct Porsche part numbers. 911361020 / AS1062 / Fox head. All of the other stampings look exactly like most Fuchs pics I see on the forum. However, only one wheel has the number 42 stamped in the raised box. Three wheels are blank in the raised box. I have no desire to misrepresent these wheels and I'm not able to find any info via a search here. Any guidance would be great. THANKS!

[rattlsnak]

Can you upload some pictures of two different ones?

[RI 3.2]

Thanks for the response. Here's all 4...

[Jack Stands]

Is it possible that some were just not stamped by the manufacturer? Hans had a bit too much bier on a Friday? ��

[brianlay]

Are the date codes similar?
This could be a set of wheels gathered from various production dates

[rattlsnak]

Yes, check date codes Maybe one has been replaced in its lifetime?

[RI 3.2]

Thanks for the responses.
Date stamps are : 4786, 4886, 5486 and 4085.
OK so the one wheel that has a production date in the year previous to the other three (4085) has the "42" stamp.
But how would staggered production dates account for the missing stampings?