No need original Company ID card , SSN or any cards. If you want, put the photo copy of it. They will take it out and give back to you, if you put the original cards.

Get the copy of all the documents filed during H1 and staple it all (that includes labor approval from DOL i.e your salary verified by DOL) you know what I mean. They did not checked it but I kept it. You might want to take the receipt notice too (the one you get before your H1 petition).

I guess the Firm Registration document means your consultancies' Registration with US gov. If you are directly  hired by well known companies then you won't need it. I did not put this.

Good Luck Siwani and everyone.