Build Records

I did the same thing as you, sent for a copy of the IBM card.
I also asked for a blank readable IBM card, which I got.
Sent all the papers to "Data Tag" who made a copy of the fendertag.
The info I got from " DataTag" was among other info.

Code P6 = outside remote mirror
Code M2= line 2 build
Code T4= performance gauge

Can you please post a clear picture of the blank IBM card?
Do you know what "line 2 build" means?