My first paintbox is up!
Here's my modified cutting scheme, in case anyone's interested (not to scale! just an illustration!)
Worked with stacking two colors, just like in the instructions. I started by cutting the two 7x3 and 8x6 sections from each fabric, then stacked each size with its partner fabric for easier cutting. From the 7x3 I cut a 7x1.75 strip, resulting in both outer strips being done.
Then I stacked the 8x6 fabrics, and cut a 3x6 strip. Leaving the fabrics in place after the cut, I sliced myself a 1.75x8 strip (giving me 5x1.75 and 3x1.75).
I removed those two newly cuts, and sliced the fabrics still lying in place for a 1.25 strip as well. Again I removed the newly sliced 1.25's, and also the 3x3 square bit at the bottom.
Then the remaining bit gets a 1.75 strip sliced off, and we've got all our pieces! And saved almost enough fabric for an entire second pair of blocks...