Blind squirrel,
It took 2 & a half months for the letter arrived, & I already had the vacation planned anyway so it was 3 week since letter to appointment.
They were very good at the Springfeild FSDO. Took 25 mins to complete paperwork yesterday & we did it electronically.
IACRA is the program to do it through. Google it then set up a password then add you details from you existing FAA licence. When you come over it speed it up a bit & they can verify it faster here.
Hope this helps.
Regards Trevor