Hi tourman68
According to Martin Painter's excellent Comet book "The DH106 Comet, An Illustrated History":
The Comets' C of A was withdrawn on 9th April 1954, the day after the Stromboli accident. Apparently, 6 of the Comets were in service with BOAC (6 in addition to those that had been written off) at the time of the grounding, at various locations on the BOAC network. Interestingly, G-ALYS is listed as "location not known" at that time, so your information fills in a gap there.
The book states that in 'Late April 1954, specially briefed crews were dispatched to collect the stranded Comets returning them to London and subsequently to Hatfield and Farnborough [for testing]. The empty aircraft were flown unpressurised and at a lower altitude.'
G-ALYS was allocated to the R.A.E. at Farnborough for testing of fueling system & structural tests. It was eventually scrapped there around 1961.