Immigration Site

Hi All, I have my I-140 approved back in january (EB3, TSC), but for some reason the laywers did not receive the letter (neither it was electronically updated I found out this today talking with the laywers).

I talked to them and they told me they talked to USCIS to see what happened with it, if it was wrongly send (sometimes papers stick and they end up sending it along with another one someplace else and they dont return it or it got lost in the mail which is not likely but possible).

The thing is that it has been approved for 5 months now and the approval notice letter was issued and we dont have it in our hands. Laywers said to call them next week since they will decide if they were going to ask USCIS to send it or ask for a duplicate, but duplicate can take more time.

I know on my end about the FOIA, that I have the right to request for a copy, and I was thinking maybe if I file a G-639 to get a copy of it then I can finally pin down my PD. (My company is huge and they move sooo slowly so i believe if it doesnt hurt anybody taking matters in my own hands would be reasonable and I will get it faster)

Questions:
1) Do you think is a good idea? yes or no and why
2) would my employer know about this when they talk with USCIS or they dont tell them?
3) DO you know about how much would the USCIS charge for this? (its unclear in the site)
4) About how long it might take?
5) Can I do premium processing for this?

Thanks!