I 140 - Coworker Reference Letters

[mahajar29]

My perm got certified last month and now I need to file the I 140. 

The issue is that I switched quite a few employers and my attorney asked me to get reference letters from coworkers to validate the time period of employment. One of my early employers from back in 2010 -2011 is refusing to give the letter, I was with them from Nov 2010 to April 2011. I was on F1 OPT EAD and he didn't really have any paper work to onboard me while looking  for a project for me for about 3 months (Nov 2010-Jan 2011). Now he says since there is no paperwork he cannot issue my any letter even though there is a W2 I have with his company name for 2011. 

I took a letter from my recruiter from that company but since that guy left the company in Dec 2010 and I need till April 2011, he did not put in any dates. Now my attorney i saying that my I 140 may get denied based on this unless I get a coworker to cover the period of work which states that he worked there in the same company when I joined and was there when I left.My attorney is asking me if I want to risk it and move forward.

Has anyone run into an issue like this ? How likely is the USCIS to actually check on co workers and the actual dates of employment ? 

Any input will be appreciated.

[Arjun123433]

Currently USCIS is very strict while looking at experience and issue a RFE asking for letters on company letterhead