i think the very earliest version of this did have a 1m near focus limit, detachable hood, and possibly (not sure on this) an E58 filter like the earliest f/1 Noctis.
the second version was E60, .7m near focus, and built in hood. almost all of these until the end were made in Canada.
the very last version (and not really a change at all) was made in Germany. some say that this may be slightly lighter but, if so, it is still a beast of a lens and the difference is negligible.
the 75 Lux is one of the (if not THE) most difficult lens to focus. calibration must be perfect with your body, etc., and even then.... there was/is a bias towards the German model because many people felt this was more solid and less prone to shifts, much in the way that the chrome model is touted for the 35 Lux.
i've seen many beautiful shots with the Canadian version and many more of these were made. i can't honestly say that it is any less of a lens -- though I did actually pay more and get a German lens as i was quite skittish about buying such a difficult lens without trying it first. (i had, however, tried a German model and shied away because of the cost and then realised i had to have it but it was sold -- so i was a little superstitious and was trying to replicate the lens i lost.) i'm usually not a snob in this way, but for the 75 Lux i was.
if you have a chance to try it and it works perfectly on your body and/or trust the seller or are willing to pay to have it recalibrated, there isn't a reason not to get a Canadian version in my mind.
it's one of my favourite lenses of all and, even if i get tempted by the much lighter 75 Cron, i would never let go of this lens. it's one of my "over my dead body" lenses and it's quite obvious why this was Mandler's favourites (remember, too, he was actually based in Canada).