lcauser,
I have done the same thing. My 140 got approved but never received the copy in the mail. We need copy of 140 to apply for 485 (before the concurrent filing was in place).
Then my lawyer filed I-824 (application for the duplicate) but we never received it and we did not even expect for that. But we can not delay the 485 process.
So, my lawyer drafted a nice document stating every thing and attached the copies for the 140 application, copy of the 824 every possible thing he can think of.
They have received my 485 application and I got 1st finger printing notice.
But from then on not 2nd FP. No RFE. But that is different story.
I am not sure I have answered your question or not but I have shared my experience in related to 824, thought might help you.