One thing I have learned through years of trial and error is "why make a substitute for something when the real thing is so accessable?"  As a music teacher can't you ask the school to allow you to borrow a mic stand?

A "forties" style mic would probably be an RCA44 (the kind you always saw Bing Crosby and Bob Hope use) or the RCA77 (it looks like a very large Tylenol capsule in a "U" shaped metal stand).  These are the two "de-facto" mics of the forties era of stage and broadcasting.  They are collector's items and as a result, they're quite expensive.  Even the replicas made by AEA are outrageously expensive.  I have seen the RCA77 "imitated," using small plastic display domes attached to either end of a soft drink can (they are very close to the same diameter) and then covered with contact paper that had a grill hole pattern on it.  They were suspended in a "U" shaped metal cradle that was attached to the mic stand.  From any distance at all, they looked convincing enough to pass the audience's notice.

I am using all of my stands for the real mics.  They are also pretty heavy and I have choreography planned for the "fake" ones.

Thanks,