Yes I'd agree with blackheart. Old
school means the approximate era of the design of the gun.
Old just means old.
In my safe I have one gun I put together from an action made in 1900 A Lee Speed copy. Here it is before I did any finish work on it
OLYMPUS DIGITAL CAMERA by
Steve Zihn, on [bleep]
I also have 2 flintlocks one of which is of a style made in about 1755 but I made the gun in 1995. here is what that one looks like.
My Rifle 3 by
Steve Zihn, on [bleep]
The flintlock is of an older "school" even though it's 95 years younger then the action of the 303. But the action of the 303 is way older.