Go back another 20 years to 1979:

Calendar
Round Event Date Winning Time
1 Mintex International 23-25 February 2:33:54
2 Circuit of Ireland 13-17 April 8:29:29
3 Welsh 10-12 May 3:25:53
4 Scottish 9-12 June 4:44:30
5 Manx 14-15 September 3:38:40
6 Ulster 19-20 October 3:27:05
7 RAC 18-21 November 8:03:38
I watched a few of those - they were before my results days!