It's not pretty. There's the Restricted RadioTelephone and then the Restricted RadioTelephone-Limited Use. The Limited Use is for foreign nationals who are NOT working in the US. I think what you've been trying to fill in is for the license for the aircraft's radios. If you want to mail your paperwork to them, try this:
FCC Form 605
About half way down the page is a box "Applicable Schedules ..." with 6 sub-boxes in it. The fifth sub-box is "Commercial Operators, Restricted ..." In that box is a link to form 605 and to Schedule E for the RR or RL. In block one of form 605 enter RR, block two enter NE. It's going to no or N/A till you get down to entering your name and data at block 10.
On Schedule E tick the last box (RL), there are three N/As and then the last box.
There is also a form to send with your payment.
To do all this online you have to create an account with the FCC. Start here:
FCC Universal Licensing System (ULS): ULS Home