Many thanks DaveReid for your input. I have seen these dates quoted previously, however as young school boy I used to cycle the 10 miles or so from Dereham to watch the flying at Watton in the period 1967 - 1969 and saw numerous Varsities and Canberras but never a Hastings. Or maybe I did but cannot now remember.
Also thanks to Ian16th for the link and useful tip. I will give the site a visit. I have another programme that will do the same thing but I don't use it much as its not particularly user friendly.
QP