1, 2, 4, 7, 10, 12, 13, 14, 15, 16, 17, and 18. A couple new bunkers are being added to #11, but otherwise, that's essentially the same, and I think some bunkers were added to #9 over the years, but otherwise looks the same. Of course, some tees have been added since his design, but I wouldn't consider that as enough of a change to say that the hole isn't a Ross hole anymore. For example, #7 was 438 yards under his design, and has been stretched to 481 from all the way back, but the hole remains as he built it.
Matt
there was a big renovation around 2000. #4 the fairway bunker designs were copied and moved in towards the fairway about 10-15 yards. #13 fairway bunkers moved in on the right. #14 (my favorite Hole) used to tee off out of a chute of trees (and i don't like trees) @ 450 yards, really Cool. Anyway they extended the fairway bunker on the left about 40 yards! #16 the fairway bunkers were moved in. #16 looking at original routing overviews looked like it had much wider fairway short right of the green. #17 Fairway bunkers were moved in towards the fairway. They also shaved fairway so that you could see the green from the right side of the fairway. Creek used to run through the hole, they covered it up. they also took slope off green prior to 86' PGA i believe (not sure when). #18 the church pews to the right were added in 2000ish renovation (don't know if they were original. The 2000ish renovations were really solid, from what i have heard and the wall built to block #1 and #10 (which i have seen), and adding bunkers in between #2 and #11 to look like #1 and #10 (is like fazio copying himself on #3 and #5) and is a miss allocation of resources (IMO). Redoing #3, #5, and #8 would make much more sense (IMO). Anyway, Inverness is a course you either love like i do or you think it is overrated. I miss the flash faces on #18, even if they aren't in the original design. #9 at Radrick reminds me of #18 at Inverness!