I just now got an email from my lawyer and he said exactly what you said in the previous post to submit the 140/485 without the LC. My lawyer (I am glad he is willing to do this) has left the message for the certifying officer and saying that he is even willing to come to DOL office to pick up the letter if it has not been mailed yet.
Here are the exact words from the lawyers email
I have left a message with the analyst who approved the case, Elizabeth Sledge, and will send her an e-mail as well (please do not contact her directly as she will not appreciate it) asking if the certified copy has been mailed out yet. If it has, Ive asked her to confirm the date it was sent. If not, I have offered to come by and pick it up personally.
Worst case, we will go ahead and file the I-140 and I-485 without it. We will get an RFE hopefully asking for it and well have at least 30 days to provide it. There is a possibility though that they may send everything back and not accept the filing without it. It really depends on how closely the filing clerk looks at it. Then well have to re-file just the I-140 alone, and wait to file the I-485 when your priority date is reached. In the meanwhile youll be able to extend out your H-1B and H-4 status as long as necessary