Thanks to everyone for the input. When I purchased this sword, I bought it for the fact that it was a reasonably priced, signed, and healthy wakizashi...I've not yet bought an unpapered blade based on the mei.
That said, I still think this one has a shot at being the nidai...the boshi is spot-on for the one Kanemoto is most well known for, the hada seems right, the mei is at least close (any additional comment being welcome) and the hamon is also at least close. It is my understanding that Magoroku's sanbon-sugi evolved during his career, but is generally irregular, and the "points" of the hamon are generally more rounded than later generations. I would expect to see, on a late generation kanemoto sanbon-sugi, a "regular 'two short and one tall' hamon"...this one is pretty well controlled, but does seem to fit the bill as irregular in that, in the large part of the hamon, there doesn't seem to be a strict adherence to this pattern. I'll see if I can take another pic or two to show some of the more "irregular" areas of the hamon and post them tonight...
Thanks again for all of the input, and I hope for more.
In the end, as is so often stated here, "Only shinsa will decide".