Oh Button Holes!

Please help!
I have knitted the welt and cuffs in full rib as the wool is very fine and to this enabled me to get the correct stretch required, but I can find no instructions on how to make button holes in full rib, either in my knitting machine instruction book or the ribber instruction book.

I have found horizontal button holes, but the finished piece is too thick. I think I need to make the front bands in full rib to match the welt and cuffs but I can only come up with loop button holes as a second best option, and sew and cut on a sewing machine as a third option.

Anybody got any ideas?