I've just flown VS in economy on the 744 (to/from St Lucia, returned earlier this week).
Don't know the seat no's, but be aware that if you want to occupy these seats (at least the ones with legroom by the exits) you will have to pay! (50 GBP per sector I believe). Seats by the bulkheads will normally be reserved for people travelling with babies (as this is where the skycot shelves are)
Letters re. this "offer" were being handed out at check-in at LGW.
Bear in mind that if you go for the window seat by the exit, you will have a very large box (which contains the emergency slide) in front of you! Also, quite a few of these seats are right alongside the galley.
The CC I discussed it with considered it a rip-off themselves!
(most of these seats on the sectors I flew were empty).