I think I've identified the leather jacket worn by Jack Dalton (bruce mcgill) throughout the series. It's a Banana Republic brand Leather Flight Jacket with a detachable "fur" collar, bi-swing back, insulated lining and wool/nylon knit waistband & cuffs. When compared to the one Jack wore, it looks spot on.
Now granted, the image below is not the clearest, as they were taken from a 1987 Banana Republic catalog, back when the images of the clothing, shoes and accessories were sketched rather than being actual photos of said items.
Given that numerous other pieces of clothing worn by Mac and the various other characters on the show, I'm confident my identification of this jacket is accurate. If I find out more about this jacket I'll be sure to post it here.
Let me know what you think.
The image of Jack and Mac was the only full body picture I could find online.

"Jeep. My Jeep? What are you talking about? Penny! My Jeep?" - MacGyver
"Look at me. I'm a hurtin' guy! I'm beat up. I need a month's worth of sleep . . . and I need a haircut!" - MacGyver
"It's been said, 'The best gift a man could ever give another, was his life', Jack Dalton was never one to settle for less than the best. Thank you Jack." - MacGyver
"Reboots are born out of the lack of imagination." M. Lance Frank