I unfortunately have blown away dozens of MLVs, except for a choice few, and have found that MLV App's "Force Vertical Stripes" fix does wonders for that footage.
Is there a way to "re-wrap" my already exported DNGs+WAVs back into an MLV, then re process it through MLV App to eliminate the vertical stripes issue?
You could try to import & transcode the DNG sequences back to MLV - in MLVApp.
I did that this evening in MLV App 1.1; it worked on half of my shots, but keeps choking on 7-8 other clips. I got around a few problems when the shot got cut due to an buffer overrun error on the 5D MKIII, cutting the shot short as the CF card filled up; I deleted the last few black frames from the sequence which seems to help. The 7-8 other shots are still not working, producing a "Could not open file "filename.MLV" error each time. I have tried this with deleting everywhere from the last 5 frames, to the last 100+ frames and it's still throwing errors.