You are correct--the BOM states Q1-Q4, but it requires 5 2n3904. I haven't been to Radio Shack in quite a while so I don't know if you will get lucky there or not. You could always put a call out in the new "Parts Jar" section of the forum---I'm sure someone can get you one. I should have quite a few myself, so I can drop one in the mail to you.