Welcome to our world! In our 72 Sovereign
, our wing windows also are two different frames. In fact, they look exactly the same as your two frames!
Probably for the same reason, one of the wing windows was replaced long ago, and the frame style changed. The original wing windows in your 72 would have been double glazed, as would the front center window. In our trailer, the inside pane of one wing window was broken out and the outside pane on the other one was broken out. No idea what the story was there.
Until recently, once the gaskets failed, you had no choice but to use vulkum to seal the window, which is what I think you're calling wet gazing. But now, VTS carries the proper size window gasket for 1970 trailers. I wish they had carried that 5 or 6 years ago when we were re-sealing our windows. Would have made life a tad easier.
To re-gasket the one window, you'll need to remove the entire wing window from the trailer, take the frame apart, clean out all the vulkum, and then put the frame back together with the window pane and gasket.
If it's not leaking, I'd be tempted to just freshen up the vulkum rather than pull the window out. But, that's just me.
Good luck no matter what you decide to do.