This one is an '87. I have a '90 also and that shows the differences that jcrntx mentioned, plus some. I'll have to look more closely at my lanyard loop...I don't recall seeing an obvious difference. Although I recall something about one style is aluminum and one is steel, maybe? I've also seen some with what looks to be a 3rd style of mag release. It's chekered, not serrated...but I guess it's possible somebody did that themselves. In my spare time, I've been trying to collect photos of the different model years and find differences, etc., and do a little historical research.
Back to the grips
...Mine look pretty much like the pic that Vinatge used, from a color perspective...more brown, not orange. The close-up pics I posted look a little more orange than they actually are. They are nice darker walnut brown more like the "full gun" pics I posted.
By the way, Vintage also offers repro plastic grips, and can do them in different colors or an additiona charge. They list them as 1985 and 1990 styles, so there must be some differences there as well.
--Otter