Do a search for Juzek. There are a few threads. From what I've learned, Juzek labeled basses were imported by Juzek's NYC company, Metropolitan Music, and sold to the NYC school system and probably others. The business started in the mid 1920's. They were made in large part by Wilfer, in Czech before the war, and Germany after. The Juzek name is a trade name. John Juzek never handmade a bass.
Master Art was their highest level bass, but the "real" master arts had violin corners, which yours does not. I have a bass with a master art label, and it is also gamba shaped.
There is also a lot of info on www.smithbassforums.com
. Ken Smith knows the Juzeks and their history well.