AF J seats are out there.
I just ticketed JFK-CDG-DXB rt in J on AF in December.
I found O inventory using KVS and then did a multi-segment search, by schedule, on dl.com.
This was the only way that I could get the AF flights to come up.
Once I had all my flights, and clicked to ticket the itinerary, an "error" message will pop up. It will give you your PNR, tell you that your flights are on hold, and that you have to call DL within 4 hours.
Considering all the usual award ticket difficulties on dl.com, this was pretty seamless.