where did you get this pattern because i've never seen a piecing pattern that didn't include the 1/4 seam allowance in the cutting directions.
i've seen it for applique but never for piecing - is it a super old pattern made before the addition of a seam allowance began common practice.
i would just continue to make these size blocks since all the fabric is cut already.
then you can fill in with more log cabin blocks to reach the size you want or you can add other blocks in with them.
those log cabin blocks would make an awesome border around a center design like a star.