Yeah, it's tough to find specifics about any of the pre-'05 neck profiles. For some I found measurements, but even in those cases it can be difficult to determine what profile it was. Of all the info on the wiki, the neck measurement/profile info is maybe the least complete & accurate. That doesn't bother me too much since I know that even between necks on two different examples of a particular model there are variances, so the info provided is a guideline at best. I would assume that the more recent necks are a bit more uniform than the ones from the 80s and 90s.
Pre-2005 J Custom necks are difficult to correlate to any mass production neck or profile. There is also the fact that Ibanez uses the name "Wizard" very loosely. Here is what you see in the Japanese catalogs.
1995: Wizard SP, 3-piece maple
1996: Wizard Special, 3-piece maple
1997: J.Custom, 3-piece maple
1998: J.Custom, 5-piece on RG1880, 3-piece on RG1680
So why did they change the name in 1997? Because the RG3120 came out and they needed to differentiate the Prestige Wizard on that guitar and the J.Custom neck. It's exactly the same neck other than the logo. If you've played a 3120, it's not really a Wizard either. It's basically a thin neck, but the profile is not like a Wizard, but it's closest to that and Wizard is a name that means something to Ibanez customers.
01-04 necks really have the least in common with any production neck. They're just very different, although they nominally are called Wizard and Ultra. The neck on an 8670 is the thinnest neck that had ever been put out. But it doesn't feel that thin because the profile is so different than a Wizard. I had an 8520 for a while and while that was nominally an Ultra, it never felt like that. Probably more like a Jem.
Starting in 2005, the neck is basically what it says it is and would be comparable to a current neck.