The Jaegers I am familiar with are styled a bit differently on the barrel end of the stock. Basically less ramrod is showing and the lock seems a bit off. Generally Jaegers were 54-62 cal but really they could have been anything. Both smooth bore and rifled were also both traditional.
Either way it is a strongly Germanic gun. My thinking is it is more of a Fowler than a Jeager. Being smooth bore and a larger yet caliber of either .66 or 16 gauge. It is close to either of those and .05” off was not uncommon for caliber diameters.
It is a great example and would be a particularly interesting piece if it was, in fact, a guild gun.