In my club, GMLGC, we have several members who have seen many original Hawken Rifles and shown them at the Hawken Classic. They have studied when they built their rifles. They pretty much agree with the conclusions made by Hanson.
Jake Hawken and James Lakenan were pretty well documented as being in the gun repair business. Jake and Sam became partners in 1825. Not many rifles are documented as being made other than the one for Ashley in about 1825. It wasn't until later that the clientele of the Hawken Shop could afford their rifles that cost three to five time the cost of a similar caliber eastern rifle, that the brothers could get past the gun repair business. Pushing innovation, their rifles were produced to use the new percussion cap that was demonstrating improved performance. Because of the cost of a Hawken rifle compared to the factory produced rifles by Leman, Tryon, Deringer and others, the most likely rifle seen rifles would have been from one of the East Coast builders. While there might have been a Hawken at the first Rendezvous, it would have been the only one of about 30 to 50 other rifles and many smooth bored guns. One of the reasons for my decision to build a Deringer rifle in flint for my Mountain Man days. Yes, previously, I did build a later J&S type Hawken. I was much younger and stronger fellow then and toting around that 12 pound rifle wasn't the chore that it is now.
