Many times the threads has become worn from riding with a loose upper race or crown nut. So it could be that somebody cut the damaged part off and used a later version race and crown nut. Or your crown nut could be a part of a steering damper?
If you decide to repair be sure to check the crown tube (edit:fork stem) weld to the spring seat and perhaps change the tube in full instead of trying to extend the one that is sitting there. George routinely checks the fork stem in a press/pull jig and found that some of them breaks off the weld really easy.....
The fork stem on the fork that I have here extends 203mm (8") long from the race seat. The 101 fork leg is -about- 678mm (26.7") from top to bottom, and about 666mm (26.2") to C/C pivot hole measured with an old foldable ruler on a very used fork! The Indian riders drawing of the Chief fork shows 26.5" to C/C of the pivot hole. It could be the same as a new 101 fork, or not -or within manufacturing tolerances. I can't check that up.
It is kind of important that the fork stem extends above the handlebars and that the crown nut is tight, because the handlebar clamping of the fork legs and anchoring with the fork stem is very essential to stabilize the fork.
