George Stoudt knows what I'm about to say:
Back when I was 18 (that would be about 66' or so) I bought my first woolrich suit.
They'd "improved" it by adding this silkish (nylon) lining with some sort of thin polyester insulation inside.
That danged thing was a misery. It was so much thinner than my grandad's woolrich or the ole "macinaw" that you could put the collar up and it would nearly cover your head!
Being thinner, on stand, it wasn't as warm as traditional woolrich up to that time. Being lined with nylon and some insulation, it was hellish hot walking.
If I ever came across an old fashioned, un-lined woolrich suit that fit my expanding form, I'd buy it sure-nuff.
We used to make an annual pilgrimage to Woolrich store in Woolrich...but when they were bought out and moved, I began finding other products.