Are all of those "standard" issue? I have the one at the bottom of the picture, I guess it is 1/2" NPT x compression?

You think this would fit as a one part replacement?

http://www.ebay.com/itm/380863173244?_trksid=p2055119.m1438.l2648&ssPageName=STRK%3AMEBIDX%3AIT



1955 1st Series 1/2 ton