I'm not sure about a regular old style neck working on those. There's no fingerboard overhang on them if I remember right. Where is the overhang of the regular 24
fret necks going to go? A 24
fret neck with the extension cut off might work, but since there were 22 and 24 fret versions of the 540PII, you'd have to know which version you had before you could start looking for a neck. --Jason