I bought a wool A-1 and a US Navy zippered deck jacket from Spearhead Militaria recently. The A-1 is pretty nice quality for such a low price, and the size XXL fits me perfectly (I am 6' 1"' and weigh 210 pounds, usually wear a size 46 Long jacket). The Navy deck jacket isn't bad, but I found it a much looser fit (and only a size XL...go figure) especially around the waist. Plus, the jacket length seems a tad short (while the A-1 is spot on). As far as authenticty is concerned, some A-1 jackets from WW1 were wool and some were leather. IMHO, there are too few surviving examples or clear period photos of these jackets to make any kind of generalized assumptions regarding specific manufacturer's details.
For the price, you can't go wrong!
For the price, you can't go wrong!