Conn Alto Low Pitch Question

It's today's standard, A=440.

I'm a beginning player, using a Conn Alto made in 1921. Under the S/N is stamped the letter 'L' which I understand means low pitch. I'm getting conflicting info from two local sax teachers, one of whom says that low pitch is today's standard and the other who says that he thinks low pitch does not correlate to the pitch of today's (or most of yesterday's) saxes. Maybe someone can tell me which instructor is

It's today's standard. Bear this in mind when dealing with saxlore from the second teacher.