OMG! You’re not going to believe this, but I re-purposed that band. I kept holding it up to the front and measuring and it seemed like the exact length that I would need for the button band. I pulled off the lace part until there were 2 rows of stockinette left above the ribbed edge that I had before beginning the lace patterning. I rehung into the row below which worked perfectly because everything was well steamed, and stitches set, leaving one full row of stockinette across the entire piece. I removed the last row, did an RTR and knit a row so I had that nice garter stitch ridge, took it off on the garter bar, hung the left front, turned the band and rehung it and presto! my button band! I did do a swatch of the buttonhole and I went with the 15mm (smaller), 2-stitch hole rather than the 20 mm, 3-stitch hole. I thought it suited the size/width of the band better than the larger one.
BTW, you know how I like to name my projects, this one is called ‘Pocket Change’.
P.S. I'm watching 'Ozark' on Netflix - I'm really liking it and I'm becoming obsessed with a long cardigan that the Laura Linney character is wearing in the 7th episode - watch this space!