Dont get excited, the check being cashed is the confirmation your paperwork has been received. My last NFA purchase the check was cashed in Jan, I went pending in May and was approved in July.
At best the wait is 2 months from check cashed, and with the election coming up and 2 gunbanners running the BATFE is pretty backed up from what I have been told. I am waiting on 2 Form 4s myself...
well i got my class 3 papers with stamp friday nov. 7th i sent it out on aug 18th but i still waiting for a retractable stock that i ordered on aug 20th i called today they said i should get it next week.