Hey big daddy, you've got it right. DON'T worry about it. And another thing. There's only two gauges you need to headspace a Lee Enfield and that's a .064" GO and a .074" NO-GO. Borrow someone elses, check your rifle and give them back. And then use it on and off for the next five years or so and if you remember it in 2014, you could test it again!
Just ask yourself how often the Russians check the CHS of their AK's. I'll tell you what....., they don't - because there's no formal figures out there by which you can make the gauges. There's lots of guesses...........