Hum. Is this fix-able?

I wanted to make a pieced back for my Granny Mania quilt.  I like to make pieced backs as it gives me a little room to play with a new idea before committing to a full project.  Today I wanted to try to replicate this border that I liked in the Collaborative Quilting book, but changing the sizes from 4 inch four patch squares to 11.5 inch pin wheels.

I worked out all of the math for cutting and was feeling confident.  I made four pin wheel blocks and was feeling pleased with myself as the points were matching nicely.  Maybe a bit too pleased as quilt karma came back and bit me.  

I wanted to make two strips like this and stitch them directly to one another.  That would give me the four pin wheels in a block with a diamond shape in the middle.  The edge would then be filled in with Kona Coal.  Pretty basic.  A nice little medallion in the center of the back.

But then I started looking at the blocks a little closer.  And I realize the points on the edge of each pin wheel block will be lost when the two strips of pin wheels are put together.

Or worse, that the Coal, when folded back and pressed, did not come to the edge of the block so I am nearly 1/4 inch short in fabric.  

Of course, when I look back at the original image in the book, their points are incredibly close to the edge of the block as well.  I don't know how the authors didn't loose the points when piecing the border onto the quilt.

I have one half of the back to piece yet, and I can already see that the blocks are on track to having a point directly in line with the edge of the Coal.

So, here is the question.  What can I do to fix this?  Do I just rip them apart and pull on the Coal on a bit to extend over the pin wheel point and give me a 1/4 inch buffer along the edge?  The Coal is cut on the biased edge, so there is a little give.  Is there a better idea?  I'm happy to rip it all apart and start over instead of loosing those points, but I don't want to waste the Coal as it's a large amount of fabric to just toss aside.  Any ideas, guys?  Help!