While searching the internet for last crusade pictures I've found this one.
I don't know exactly but it's the only picture where HF had the jacket zipped up a bit in the movie. I can't remember the scene in the movie. This looks really like a big neck opening. Can Wested also made the jacket look like this? Has anybody requested this before?
Back to your question, you can ask Wested for any size collar opening you like. That way if you have a really thick neck you can get it made to fit. (Didn't I mention thi to you once before?)
I'm not sure exactly, but I don't think Indy ever really zipped his jacket all the way up. Even in "Mystery of the Blues," it wasn't all the way up. Either way, the jacket looks good unzipped or zipped!
He is RUNNING in this photo. His jacket moving up and down, thus giving the appearance of a larger neck opening. Try running up to a mirror with your jacket zipped like that and you'll see the same thing.