Vintage Home Made/ School/Shop Made Steel Screw Clamp

This clamp doesn't appear to be factory made though I am not 100% on this one, these were sometimes made in high school machine shop class as a student project. 

[Please Look at all the pictures they are part of the description] 

                                                                                                                                                                                                                                           [B1-F1-AV-S2-4]