Thanks for that . The reference you supplied might turn out to be useful in the future .
Actually i think I shall be alright with this work .
I have taken off the eyepiece and can now see that the focusing ring is held in place by the inner housing of the erector lens itself rather than a simple nut as with Hensoldt and Zeiss .
Dunlap explains all this in his book GUNSMITHING but rather superficially .
I intend to proceed as with my experience with the German scopes and hope that Kahles copied them .i.e. after removing the focusing ring I shall remove the adjusting turret and see if it is much the same as the Hensoldts.
I hope that the graticule cell can be pushed out of the tube without damage as the Hensoldts permit .
I shall report on my progress or misadventure at a later date.
Thanks again .