went back and forth the other day about the model g and the bassbucker, the this guy posted a pretty interesting pic of one cracked open, he swears its a x2n with pole peices instead of blades..
http://www.talkbass.com/forum/showthread.php?t=569920&highlight=bassbuckers
This is an old thread, but that was referring to a post of mine at TalkBass. I was saying the Model G is an X2N with poles. That photo is of a Model One. It uses the same bobbins, but is wound differently.
I know the G is the same as an X2N because the coils have the same resistance reading as an X2N. However, the X2NB is not wound as hot. I've converted some Model Gs into guitar pickups by adding blades.
You really don't want an overly hot pickup on an bass. As you wind a pickup hotter, you end up with a bandpass response. So you have a big hump in the mids, and the highs and very lows get lost. You also have to think that a bass puts out a lot more signal from the larger strings, and that hot guitar pickups are made extra bassy to give the guitar some balls. Bass already has bass! This is why the vintage T-Bird pickups sound so good. They weren't wound very hot and stayed nice and bright.
I make guitar humbucker size bass pickups. One recent customer replaced an X2NB with one of mine and said:
I've had a couple of rehearsals with the pickup now, and it's a keeper. It is, of course, lower output, so I did have to increase the volume of my amp a bit (went from 2 to 3 on my VBA 400, and per your suggestion adjusted the pickup close to the strings - a lot closer than I had the X2N-B). The tone is WAY better/balanced, so I also adjusted the EQing on the amp. It sustains longer (I always thought pickups had little effect on that, unless they were super low output... live and learn, hehehe...), it's MUCH "clearer" sounding (by that, I mean I can hear the individual notes a lot better now), and as I said previously, has more "girth". All in all, an excellent pickup.
That's not posted as an advertisement, just to point out that some of these guitar pickups masquerading as a bass pickup are not always the best choice tone wise.