I disagree 1792 contract rifles were heavy and clumsy. They were Lancaster style rifles, most made by Dickert. the 1792s were essentially base model hunting rifles. If 1792s were heavy and clumsy so were the rifles highly imitated today. The Stith L&C rifles might be designated today as M1792A1, but the evidence for them is speculative. As until 1803 the needs of those going into the great unknown of the west weren't known, at least not at all well known, I personally doubt the 92s were converted to the A1 configuration in anticipation of western needs. But, as a best guess of what L&C might have carried the M1792A1is as good as any other. If I wanted to make some effort to represent the L&C expedition rifles it's probably what I'd settle on.
Personally, my interest in 1792 rifles is limited to their history prior to any modification.