might as well add in my 2-cents. i went the e-start route because of age (74) - bad knees and not having the balance to kick start the bike off the center stand that i had when i was in my 20's. i chose the alton for a couple of reasons. cost, and the fact i preferred the stock look of the air cleaner. belt drive was not a driving factor. as most know, i've had my fair share of sheared (altenator mount) woodruff keys, and presently going thru the "yves" fix. as a matter of fact, should get the final machining back today, and hopefully i'll be back on the road tomorrow. as to the original question, i can say, the form, fit, and finish was without issues. overall, a first class kit. one disappointment, the inner primary case was not polished like my original, factory case, however i did spend several hours to address that aspect of the kit. installation was fairly easy - no real issues. never kept track of actual time to install, but i'd guess, one man/one day w/ no special tooling (aside from the time spent case polishing). would i do it again - on the fence on that one. i'm somewhat disappointed because of the sheared keys i've experienced. i can say for sure, that the second installation, it was done by the book, so i'm thinking there's something that's hit or miss within alton's design. it could be something as simple as a critical dimension, spacing, or some torque value, because it doesn't seem to affect everyone who's installed the kit. seems there's something right on the ragged edge that makes it hit or miss. if i would have known up front, i would have incorporated the yves fix right out of the chute. that would have been an additional cost factor to consider. i would say, anyone installing or considering tha alton kit, add a belleville washer to the sprag-clutch retaining nut, and bumping the torque about 20% on that nut. i have no experience with the cNw kit, so comments there.
hopefully the yves fix will put an end to any future issues. if i have one more woodruff key related failure, the kit comes off and i'll go back to OE stock configuration. i'll write the whole thing off as a bad experience with a so-so kit. most likely, i'll put the kit up for sale, and hopefully, recoup some of my $$$. right now, altons on stirke two, and you know what they say, three strikes and you're out!
At $300US per pound of weight when all is said and done, I'd resist a retrofit electric starter for a Norton as long as possible. 
and the "only" reason you bought a Norton was to install an electric start???? Feeling confused here.
