G4 Blind Bag Pony Sorting. Wave differences?

[Kitkumi]

The short of it is I'm sorting through all my G4 blind bag ponies and I'm trying to match up each pony to the wave it came out of. Some of them are super easy, because they have only shown up in a wave or two. Then I have a blue million Twilight Sparkles and she's in almost every set!

I'm probably going to sell off a good number of these, since I have a lot of duplicates, but I don't want to tell some one "Yes, I have a wave 1 [insert pony here]" and then for them to get it and go "wait a minute, this pony is from wave 6!". If there is a secret to making sure I sort these right, i would love to know it! Or, are all blind bag ponies created equal, so there are no differences between a wave 1 and a wave 6 pony of the same name/model?

 

[Violet CLM]

You should be able to get a pretty good clue by looking at the date they were produced, but even then not all of them have that information, and it probably won't help you with two adjacent all-opaque waves.

[hathorcat]

Part of the issue is that some of them (a lot of them) dont have deliberate differences as you know and they are manufactured so close together they actually cross over from wave to wave.

As Violet has mentioned, your best bet for any of the releases which are very close in appearance is to work to the manufacture date stamped under their foot (works to a standard julien calendar of date) that should help you out a little.