Welcome to the forum Josh !
Nice lookin' Swinger ..
I had a 1972 V-156 with same windshield set up, I had the center window, but I never used it unless it was raining or cold.
I finally just removed it .. But though about making one out of a clear vinyl and installing snaps in metal frame.
If not needed you could roll it up and place it in side pocket.
My 156 also had a vinyl curtain that covered bottom of pass thru, to completely cover front.
Picture is snaps for cover, worked well for rain and cold and would roll up and fit under bow seat storage.
Sorry no pictures of it, it was blue vinyl just like interior vinyl.
I'm sure you could find a replacement window but they rattle and have sharp edges.