Hi Rick,
On the primary side, use some placistine or putty wrapped in a piece of foil, to measure the gap between cush drive boss and crankcase, place the foil wrap into the recess and bolt on the drive in place, this will squash the foil wrappped putty to the thickness of the gap where the felt fits
Fit the felt so its lightly clamped in place,
When finally fitting the cush drive assembly make sure the tapers are clean and oil free, I usually add a drop of bearing fit as well and make sure the sleeve nut is fully tight
Then add some drops of oil to the felt
A similar method can probably be used on the timing side, My L25 is an earlier model and does not have this feature
HTH
John