SX-OAD is the only 747 still on the active roster for OA. SX-OAB, OAC, and OAE are currently "stored". The FAA has recently downgraded OA status to CAT II (?), which I believe means that OA cannot add destinations or change aircraft type to flights to the US. This was done for organizational reasons and not for safety, or maintenance issues. So until that changes, OA can only use their A-340-300's and not the 747's or A-300s' to JFK and BOS. SX-OAD is used for the occassional fill in roles for flights mostly to Heathrow, Paris, JHB and a few other destinations that currently escape my memory.
I would appreciate any updated info on the disposition of SX-OAB,C, and E.