Hair-splitting question for our resident zipper nerds

[mulceber]

This may be a question that is too in the weeds for some people, but it's been bugging me, and I wanted to hear if our resident experts on zippers. I've been looking a lot at the Rough Wear 1401-P lately (see Tim's Good Wear thread for the reason why ). According to Eastman's guide, this contract was made with the Crown M-40, and the Crown M-41.
Crown M-40:

Crown M-41:

While browsing John Chapman's CD, however, I came across this 1401-P from Jeff Thurston's collection, which has an M-42 Crown:

Note the different shapes of the sliders, and the different shine of the metal. So, there are a few possible explanations:

1. the zipper got replaced at some point.
2. the slider got replaced at some point.
3. Eastman's guide is wrong, and there were more than two different types of zippers used on the 1401-P.

Options 1 & 2 seem less likely: I don't see any stitch holes that might signal there was a previous zipper, and the tone of chain is consistent with the slider, so it probably isn't an M-42 slider on an M-40 chain. Unless it was replaced in the last few decades by someone who tried to use the original stitch holes, this is the original zipper. Option 3 is very possible - one of the frequent weaknesses of Eastman's guide is that it isn't comprehensive about what zippers were used. So, my guess is that some 1401-Ps were made with M-42 Crowns. I've been trying to find more pictures of originals of this contract to see if I could prove it, but have really only found a few, so I have no idea if I'm right. Then it occurred to me just now that this might be a fine question for our resident experts. Were there other zippers used on the 1401-P than just the ones listed by Eastman, and, if so, which ones?

 

[Silver Surfer]

As I understand it, the 1401 contract was issued in 1941. Is it possible that rw had left over 1401 labeled jackets that went out in 1942? Dunno. I do know that the third iteration of the crown zipper was made with zinc teeth (pot metal), as wel as the puller. Was the puller replaced? Possibly, but, if the example shown has zinc teeth, and the zipper was not replaced, than it is a jacket that was issued(possibly made) in 1942, as were the zinc zipper assemblies. With original a-2s, nothing is writ in stone.

 

[Grant]

One thing I've learned is there are no absolutes in this crazy hobby, so all three may have been used in the August 1941 1401p contract, but I'd bet the last pic is a replacement zip.The pull and teeth are the later zinc Crown (note the zinc stopper box). Just my two cents! Impossible to know for sure unless you could examine Jeff's jacket up close.

 

[mulceber]

Thanks guys. Thinking about what folks have said, the answer I think makes the most sense is that the zipper was replaced sometime in the last 3 decades by someone who wanted it to look like new, hence the absence of tell-tale stitch holes. Given how prone the original crowns were to breaking, it would be unsurprising if a collector needed to repair the jacket, and given the rarity of Crowns, it's unsurprising they couldn't get exactly the right make to replace it. But that's just my conjecture.