I would probably just cut it into wide strips, sew the strips together into strata, and create new blocks that way. A little wonkiness inside the blocks would add charm. I wouldn't necessarily take anything apart; I would just either reinforce existing seams or sew a new seam. I'm thinking maybe 9-patch blocks made this way.
I remember a travelling quilt exhibit that showed quilts made every-which-way by poor women who didn't have rotary cutters, etc. and who just joined fabrics they had any which way. These quilts were *alive*. When we walked out past traditional quilts from the same era, the traditional quilts looked dull and static by comparison.
In my opinion, you have a potential gem here. I wouldn't worry about the wonky seam matches. The biggest problem is simply that the fabrics are cut too big. Once these fabrics are scattered throughout the quilt, they will become much more interesting.