USS Saucy Armament

I am starting to gather aftermarket stuff for my Matchbox Flower-class corvette, and the Saucy is one variant I am considering.   I am looking for the armament she carried.  One site listed the big main gun and then merely two 20mm Oerlikons, which I surmise would be the bridge wing guns.  But there should be a gun aft, on what I see called the "bandstand" a lot, that looks like a fairly large weapon- much larger than the Lewis machine guns the original Flowers carried.  What is that gun?  I have found a lot of sites about various Flowers in a google search, including several about Saucy, but not much about the actual armament.