Copied from:
http://www.harringtonmuseum.org.uk/ThorUK.htm
The missile was still being operationally proven as a weapons system however, and nearly a year was to elapse before the next batch of RAF squadrons was declared operational with the Thor, on 22 July 1959. These were No. 82(SM) at Shepherd's Grove, Suffolk, No. 104(SM) at Ludford Magna, Lincolnshire, No. 106(SM) at Bardney, also in Lincolnshire, No. 107(SM) at Tuddenham, Suffolk, No. 113(SM) at Mepal, Cambridgeshire, No. 142(SM) at Coleby Grange, Lincolnshire, No. 220(SM) at North Pickenham, Norfolk, and No. 269(SM) at Caistor, Lincolnshire.
Five more RAF Thor units became operational on 1 August 1959, all of them in the East Riding of Yorkshire: No 98(SM) at Driffield, No. 102(SM) at Full Sutton, No. 150(SM) at Carnaby, No. 226 at Catfoss and No.240(SM) at Breighton. And it was the end of the year before the six remaining squadrons reached operational status - No. 97(SM) at Hemswell, Lincolnshire, No. 130(SM) at Polebrook . Northamptonshire, No. 144(SM) at North Luffenham, Rutland, No. 218(SM) at Harrington, Northamptonshire, No. 223(SM) at Folkingham, Lincolnshire and No. 254(SM) at Melton Mowbray, Leicestershire.
Another paragraph states that 3 missiles constituted a Sqn.
