This was several years ago, so it may not be much help. In 1996, I think, I had one done when I lived there, and bought an integrally suppressed gun.
I was in the Marion Co. Sheriff's Dept jurisdiction, so went through their office for the sign off, but through IPD for prints. Whatever- it was my first Class 3, and I just followed the dealer's instructions.
I went in, found the Sheriff's secretary, and told her my business. She said something to the effect of- "Fine. Leave it in the inbox".
I figured that was that, and I'd never see those forms again. I thought if I was lucky, maybe I would get it after some phone calls and return visits.
I think that was a Friday, but maybe a Thursday. Anyway, it came in Monday's mail! Not only did I not have to beg for it, but it was sent ASAP by them.