Hi Agrafoi,
I have never used series formulae to compute orbital elements.
But I see that the ELP theory for the lunar motion _does_ have a
version expressing orbital elements in the form you're looking for.
I've only seen this in hardcopy form, in the book "Lunar Tables and
Programs from 4000 BC to AD 8000", from Willmann-Bell:
http://www.projectpluto.com/books.htm#lunar_tables
As is mentioned there, one can download the terms used in the
series for the moon's distance and ecliptic longitude and latitude.
(By default, Guide uses these series.) The series for orbital
elements are _not_ provided on-line (as far as I know), but the
book does give them.
ELP uses a slightly different notation, in which
Lsl = D - F
Lml = F
D = 297.85020420 + 445267.11151675 t - 16.300e-4 t^2
+ 1.832e-6 t^3 - .884e-8 t^4
F = 93.27209932 + 483202.01752731 t - 34.029e-4 t^2
- 0.284e-6 t^3 + .116e-8 t^4
where D and F are in degrees, and t = (JD - 2451545.0) / 36525,
the time in Julian centuries from 1 January 2000.
Hope this helps...
Perhaps there should be an "astronomical computations" Yahoo list!
-- Bill