diburning

I have a non-frequent-flyer friend who has a ticket that appears to be part of a group booking and he is unable to select a seat. He wanted me to see whether I could help him get an E+ or an upgrade to F (he's willing to pay). So, I have his PNR and it's quite interesting.

There are 24 people on this PNR. Some people have seat assignments. Some do not. My friend does not have a seat assignment. Attempting to select a seat generates the error: "You cannot select a seat for this type of reservation."

They all have an S fare.

My friend did not add his MileagePlus number to the reservation although when he provides it, it looks like I can add it to the PNR for him.

All of the regular seats are taken, four seats are shown on the seat map as "Perm Blocked." There are four "Preferred" seats left, and E+ is almost wide open. However, the standby list is empty, the UG list is empty, and there are five open seats in F. Searching for the flight in Expert Mode shows 5 available (to be sold) up front, and 9 in the back.

Is there anything I can do to give him a seat assignment and/or get him a paid seat upgrade to E+ or F without having to call in? If not, will he get a seat assignment at check-in, or will the gate agent have to manually assign them? If it's the latter, then maybe I can get him to save his money since BE tickets would be auto-assigned those Preferred seats first, filling them before the gate agent can assign him what's left of E+

EDIT: Oh, and I forgot to add, the flight in question is the return flight of a roundtrip, with the outbound already flown. The outbound was a T fare, and the return is an S fare.