Reddit mentions of Orvis Men's Corduroy Collar 4 Pocket Cotton Barn Jacket - M - Tobacco

Look up waxed canvas jackets. That is what Arthur wears. You can get a jacket that is much better than the one from Irons, and for cheaper. Just look around, some may not look exactly like Arthur's, but it will be close and for less money.

FYI, Arthur's is a field jacket, with a leather collar.

Edit: If you are actually buying a jacket to use, you should by a nice one. You can get ones for $200 to $300 that will last a lifetime if you take care of them.

While not exact, this is close. https://www.llbean.com/llb/shop/78261?page=upland-hunter-field-coat&csp=a&feat=78268-item_page.recsdormant

https://www.llbean.com/llb/shop/18215?page=original-field-coat-with-wool-nylon-liner&csp=a&feat=78261-item_page.recsbottom

This one is really close. https://www.amazon.com/Orvis-Corduroy-Collar-Cotton-Jacket/dp/B00SQIBR9G/ref=rtpb_1/137-4500214-9955139?_encoding=UTF8&pd_rd_i=B07C2Y89RK&pd_rd_r=215dde46-c8c2-4789-9c08-791f1a31021b&pd_rd_w=xciRh&pd_rd_wg=QqCL3&pf_rd_p=5da730bb-0163-4dd7-b781-c970ec169872&pf_rd_r=RGWTRX0YMSD1HZF0MEEB&refRID=RGWTRX0YMSD1HZF0MEEB&th=1

https://www.orvis.com/p/orvis-heritage-field-coat/2kb2