Like Cosmotiger said, it's hard to tell without handling the figure.
It could be that Ral Partha had updated the figure at some point because of casting problems?
If a model had akward mould lines (like you described) or other casting problems, like sink holes, or wore out a mould too fast, these things were sometimes rectified before remoulding. Back in the day this was usually only done for high seller figures and wasn't alway announced to the public.