The Winchester A5 scope is something you don’t see much now a days. An early rifle optics that was used as a sniper optic in WW1. Easily confused with the Lyman 5A which is essentially the same optic. This one was acquired over the weekend by one of the boys in the vintage scope collectors group.
It is externally adjustable as you can see by the mounts.
I may have more to say about the A5 later this week.