Thanks all!
Yeah, I worked out after I'd shut computer down last night, that #1 was the mounting pegs for the shelf unit they're sitting beside
Thanks re the other bits.
6knights: Mainly SAE, some Whitworth, noticed a couple of BSF. Wasn't paying much attention to be honest, because as soon as it didn't show mm, it went out
Same with brands: Sidchrome, lots of various "Made in England", at least one SnapOn, lots of Taiwan & China. Sizes were anything fro very small (1/4") up to ~1".
Heart-breaking to even think about dumping them, as FiL's stuff mainly dates back to when he was a mechanic in the 1940s-50s, & I've also got some more from my own g'father, back to round the same time, & perhaps even earlier, as he was a truckie before WW2!
Mentioned them while talking to #1 son last night though & he said he'll have a look at them all, as aircraft are (virtually) all imperial measurements, so he may be able to use them