As a major builder (over 20 employees for many years), Caswell's enterprise made pistols, rifles, smooth rifles, etc. He is reported to have provided locks with his stamping to other gunmakers. Typically there is a Caswell stamp of one sort or another on the barrel, but I don't know if he always did. My conservative approach is to assume your gun was made with Caswell parts unless it can be proved that his shop did the actual build