救命呀, Xiaobaitu etc.

Suddenly got an interview appointment from USCIS local office for my 485 and my family members. My problems are, it will be in one month grace period. My problems are,

1.I had two H1 visas, but one of them I lost its original(but I have its copy), I cannot find all our three(hu*****and, wife and son) 485 receipt notice(but have their copies), so can I as CIS to send me again the origilas of them?If yes, how long it will take? and how much CIS will charge me?

2.The interview letter told me, we can "ring an interpreter if we want want, but the lawyer can be our interpreter", my English is quite good, so can I be an interpreter of my hu*****and's? if my hu*****and need my translator(that means his English is poor), it will affect his GC approval?
Thanks a lot for answering my questions