I was working the night of the Lockerbie disaster - in fact I was doing the sector through which it fell (ScACC Talla sector) along with a colleague.
Like I mentioned before, a routing that far north for a London-JFK flight is unusual but it does happen from time to time that the oceanic tracks are really quite a long way north. There are usually six tracks, each separated by a degree of lattitude (=60nm). I have seen 57N10W as the most southerly track before.
Not all transatlantic aircraft use these daily promulgated tracks but the majority do.