SATCO, Sector 29 was part of the POL/BTN/IRISH SEA Sector that was transferred to Manchester Sub-Centre, and, as Janet says, later moved to EGPX in Jan 2010. The date of the move up to EGCC is up in my loft somewhere, but was in the late 1990s, I think? The vertical limits were, and still are FL195-FL285. The Manchester Sub-Centre was re-named 'Manchester Area Control Centre' around that time.
There is a useful AIP Supplement dated 2018 here, showing all the current sector data.
http://www.ead.eurocontrol.int/eadba...2018-02-15.pdf