However, I believe that the GC card itself is the king. Seems that the GC card is attached to the I 797D. It also seems that I797 is more authoritive than the I797C.
I had LUD as "approval notice sent"; received I-797C titled as "approval notice"; Still did not get my GC card yet. Neither I 797 nor I 797D.
I have a lawyer (my hubby's company lawyer; my hubby is the principal who got "approval" two days later than me. got the same LUD and mail as mine). The lawyer received nothing recently.