Stan, You are close in what you are describing. If it does have l.C. Smith on it then it is the later gun from Baker who made the original.
Gun could be had with either 10 ga or 12 ga with 44-40 WCF (Winchester Center Fire) and later offered in 45-70 and 38 caliber. The little lever in the front is the cocking lever for the rifle. To cock the rifle, cock the left outside hammer and then push the thumb piece (rifle cocking lever) forward.
To open said gun push the front trigger forward and it should break open.