[klondike98]

Here's the schematic: http://www.nostalgiaair.org/pagesbymodel...013221.pdf

Broadcast (AM) is position 1 (farthest position counter clockwise when facing the front of the radio or farthest postion clockwise from the rear according to the schematic).  My first thought... if the switch is not moving to all 4 positions there must be a mechanical problem, a contact somewhere has gotten bent or there is something that has been pushed onto one of the switch wafers.

My second thought would be to ask... are you sure you don't have a 37-650B which looks similar but only has 3 bands.