Dating Early Harley Transmissions

[danf19]

Guys:
I have a few earlier Harley transmission that I am trying to date. I have checked the parts manuals or so I think !?!?! is there a chart anywhere or reference to help me date these. Mine have "L" and "F" in the code but I've heard of other people having transmission with other letters in them. So my interest is specific to my needs but also interested generally in understanding how there were dated in the early years say 1908 to 1930.
As always, thanks for our time,
Dan

[MMasa]

Dan
I've covered this before but it's pretty straightforward.
The letter indicates the year.
Starting with E in 1916;
F = 1917
G= 1918
H= 1919 (if there is an A at the end then the box should have the new mainshaft, clutch, etc that was introduced mid-season in 1919)
I= 1920
J= 1921
K= 1922
L= 1923
M= 1924
1925-1927 had a year prefix as opposed to a letter.
25-xxxx
26-xxxx
27-xxxx
Where the two digits are the year and xxxx is the sequential serial number.
1928 and 1929 are un-stamped.
Mark Masa