I guess the guidance system would have been based around well tried
and tested modules - hence valves.

Most likely true, Interstingly, the wiki page on Blue Streak suggests
the guidance system was more advanced that that of either the Vulcan
or Victor.

Of course, Beyond The Fringe suggested that it would be delivered by a
team of highly trained runners and renamed "Greased Lightning".


Apologies for poor focus:
https://www.dropbox.com/s/yobh8llas8...2015.06.34.jpg