Effed up sequence settings and looking for a solution

I have created a sequence using native files (do'h) and need to switch 'em up to Apple Pro Res (422). I was gonna just pancake the thing, but it turns out my sequences are in different aspect ratios. Here's the screenshots:

What I want:



What I have:



Is it possible to somehow tap the source files and get this done without completely rebuilding the sequence from scratch? I'm at a loss and appreciate any possible suggestions on this tricky situation I've gotten myself into.