I understand they were to be used to bomb Russian airfields, so we were considering pre-emptive air strikes even in the mid-1950s
I very much doubt that at that time we had sufficient intelligence to identify counterforce targets with any reasonable level of confidence. The only "realistic" and credible national strategy was countervalue, i.e. population and manufacturing. In later years, when integrated into the SACEUR Plan, what you say is closer to the mark; in terms of targeting but not timing; even then the national plan would have still relied upon a countervalue threat.
YS