[Delta scrollsaw]

I just bought an old delta 1200 scrollsaw.  There is no manual with it of course.  The jaws on the plunger are a mystery.  I can't figure out how a blade is supposed to stay in there.  Three pieces came with it they dont make any sense to me. (One is in the plunger)  Can anyone help me out?

 

[Delta scroll saw]

Hi, new guy named Charlie here.  I am considering buying a delta 1200 scroll saw.  It's an old tool and I'm wondering if blades and parts will be hard to find.