UK tech in the US? Think ``jet engine''. Did the UK ever get anything back out of that ``reciprocal sharing deal''? Uh. That is to say. Er. Next question please!
Or, the question is a bit pointless, because if there was still British tech worth pilfering they'd pilfer it, or just buying up the companies.
As to getting second or third rate stuff, well, if that's cheaper and better value than what the UK can produce, you're still better off. Or at least it is as long as you don't engage them, which is pretty much the assumption.
Beyond that it really doesn't matter who has the top notch bestest stuff. The kids that do the dying *never* have the perfect tool for the job, so procurement should stop porkbarreling under that flag. Get ``good enough'' stuff where it is most needed in a timely fashion, make sure the grunts have suitable training, and with a competent officer corps. You need all of it in a suitable mix, but you don't need the theoretical very best, and not paying too much of a premium means you get more stuff and more people to have use the stuff.
In that sense the best weapons would be fully automatic shipyards and factories and a ready stash of people to man the products as soon as they are ready. But you can only sustain that during a war, and despite superior technology there's still physics to account for.
Lewis may not have everything right, but the overall theme of a classical British half-arsed knock-off of the beltway bandits I have no trouble believing, and it's well know it's a rather expensive affliction for a government to sport.