I can only guess that in the three years between taking my TR3A all apart and putting it together again, well what is it called, "a senior moment or three years?"
I have lock washers on there and they never seem to come loose.
On the one I finished in 2006, I guess I used my photos as guides. In the case with that TR3A, it was 10 years between dis-assembling it all and finishing it.