I have a TATL itin with a 074 ticket number (KL stock) that includes NW, DL and KL flights. I had to get the ticket on short notice and nwa.com was giving me crappy options so I ended up going through a travel agent. The itin includes a DL flight on a CRJ900 (operated by Comair). I can see the itin at nwa.com but I can't select a seat for the DL flight. I tried pulling up the itin at DL.com but none of the confirmation numbers work (I tried the NW number, the KL number and the Amadeus number). 3 questions:

1. What do I do about the seat on that DL flight?
2. Will the UG process work? Is there anything that I need to do or will it work automatically? How do I even know if/when I get upgraded?
3. What should I do about checking in online? I obviously can't check in at DL.com if I can't even pull up the itin. Any suggestions?

Thanks in advance!