Hi Doug ----- I agree with all of the above. The chips are the same ... and they're different. How's that for wishy-washy? How far can you take this? I have a "Hundertwasser" chip from "Casinos os Austria" (100 somethings from Austria) which is clear plastic with a partially see-through overlay. The overlays on each side are randomly applied, so that every chip is different (or, more accurately, the probability of the two sides being aligned exactly the same in any two chips is very small).
For me, I guess the answer is probably something like, "if there is a finite (and very small) number of varieties, I will probably try to collect them". . On the other hand, though it meets that definition, I probably would not collect the reversed inserts of the two sided chips such as the one you described in your posting.
Not sure how I feel about the dovetails (??). Even if intended to look the same, though, if re-orders of a chip produce a significant variation (e.g., the Bill's Lake Tahoe $1 chips), I would collect the new chip as a variant.
My opinions on this subject, in addition to being somewhat schizophrenic, are definitely not definitive!! Best advice, I think, has been posted here by several people recently -- COLLECT WHAT YOU LIKE!! (and ignore any advice to the contrary). ----- jim o\-S