I need some serious help!

[weaponX]

I have a 1988 Model 4m that needs leveled refretted...I am not finding any info on this year/models neck radius. I have found that earlier models(early 80s) have an 11"...but i also am aware that charvel was the frontrunner for compound radius necks. If so, is it 9.5-16? 10-16? My head is spinning I want to do this right and keep it as original as possible. Please Help!