Yes it is common at the end of the end cap. I, like you, rebuilt mine (76) about 5 or 6 years ago and I think the only thing wrong was the *$#ing little O-ring in the end of the body (it was broken clean). The instructions were good, but a lot of work to do all that just to replace that stupid little O-ring.
I lived with that leak for about 5 years, but got sick of it so sucked it up and did the rebuild. It has held up since, but I am dreading the day it starts again. When and if it does, I will probably do the rack & pinion also and just spend the $. Until then, it seems to work fine (as long as I keep it well aligned and after I rebuilt the front suspension).
You can spend a little more and replace the whole unit, but it is still a lot of work to get everything off just to replace it and you still have to deal with all those hoses and the bleeding, etc. I have also heard dubious things about the rebuilt units (poor quality and might crap out shortly thereafter).
Good luck.