I have a copy of the booklet "Serial Numbers with Description of Waltham Watch Movements", the Gray Book. On a lot I find those references "LS WI" plus the marks meaning Jeweled Main Wheel and Patent 1908 regulator. I guess WI stands for Wind Indicator, whereas LS should be the more common lever setting. Am I right ? One more question : the Grade Of Material U,A,P should make an evident difference in the overall value of the movement, but it doesn't seem so on the market. This really puzzles me. Can you give me some advice ?
Thanks for your time and kindness towards a beginner.
PS: a movement in such a run should really be a nice one, isn't it ?

Mario

The U means unadjusted and the A adjusted.

I don't remember what the P stands for but it was the highest category of the 3.
Some late 12 size are marked 5P which may mean it indicated the watch was adjusted to postions.
Bob

I believe Robert is right, U is unadjusted, A adjusted and P is adjusted to positions....

Sure, that's it. But from descriptions it seems that there do is a difference in manufacture between, say, U and P, and I expected this difference coming out in market prices. In my experience this seems not to hold, and this puzzles me a bit.