What I would suggest is that you draw the actually size of the diamond block. Use that as a template. I used the stiff interfacing I could find. See if your discrepancies are from the diamond block or if it's your setting background are off. Then you will know how to proceed. Maybe just one diamond is off. If you find that it is mostly the background sections, then I would buy new fabrics and replace it. You are a better quilt now then you were in the 90s and so am I. That is what I did with a Lone Star from EB and I got it done and sold it. I have one more done in patriotic colors that I need to tackle too. Good Luck !!