I think you need to ask AM for the fare class (or ask AM for the DL reference number and then use that to ask DL).

Assuming this was from the very cheap sale a few months ago, the AM formula for RDM and MQD (distance-based) works out dramatically better than the DL formula (cost-based). This rebooking may prove unfortunate. Also AM's business class seating is more couple-friendly. I think I would have likely refused the rebook in your shoes.

I have no clue if ORC will be possible here.