You can find the catalog description of the 440R/540R in the EU catalogs on the Ibanez site:
http://www.ibanez.co.jp/anniversary/index.html
The 1990/91 catalogs don't specify the neck type for either model. Seems like the main difference was the V pickups instead of the IBZ's in the 540R, and in 91 Edge instead of LoPro trem. All it says about the neck is "maple: 1 piece" but I'd be surprised if it's not an Ultra.