Paul Jaeger was a noted gunsmith of about 50 years ago. He had some of his own products, including a scope mount similar to G&H. I don't know if he made barrels, his name on a barrel might just mean that he fitted it.
His nephew Dietrich Apel came over from Germany, worked for him, and eventually took over his shop in Jenkintown PA. Jaeger's shop was later bought out by Dunn's who moved it to Tennessee for a while but the last time I looked, clicking on "fine guns" on the Dunn's website got you Cabela's Gun Library.