Filson Jacket style 435 XL

I have never had any experience with Filson jackets but this one is very well worn, used by my stepdad in Fairbanks , AK for ages. He was an avid hiker and hunter, and chopped all his own firewood to heat their home with a wood burning stove. He may not have put much importance on money but when he bought something he bought the best, and only bought Made in America! We found this jacket in their garage and realized what a find it was but, it is just too big for my husband as he wears a Medium. It has the slightest mustiness to it but I’m sure it can be cleaned. There is a stain oil mark (?) on the back of the right shoulder. Please zoom in in photos as they are part of the description. Many pockets the two front pockets are Huge. It is an oil coated cotton jacket. I assume he bought it due to it’s weather proof qualities. I think the color is olive greenish??? Serious offers welcome.