I am always a little confused by the usage of the term "jaeger". To me it means a short barreled Germanic rifle made in Europe. But others sometimes use it to describe early rifles made in the colonies, and some would even call the Marshall rifle a jaeger though it was stocked here in maple and has a 37-38" barrel. At that point, the term jaeger becomes too broad to be a useful term for me.
After that philosophic intro I'll say that its unlikely that barn gun style jaegers were made in Europe and found their way here. So making a jaeger with Euro walnut and leaving off the buttplate or entry thimble, sideplate and nosecap woud be a fantasy rifle. On the other hand it is entirely possible that a wrecked, European jaeger rifle could have been restocked in the colonies and some parts substituted or left off the resulting rifle. Would something like this be the norm or common for anyone to own or carry? I doubt it.
Barn guns or schimmels were mostly made in a specific timeframe and location, likely for a specific clientele that is not so romantic. Farmers guns. Many re-enactors nowadays like to expand the concept by reasoning without much data that at all times, in all places, the common man used bare bones, stripped down rifles.