I used the Laguna mortiser for cutting these mortises. They’re 3/8 wide and 15/16 deep. There was a lot of heavy math trying to get a similar look in the two widths of bed—a problem you’d not face on a traditional bunkbed.
I finally decided it was an opportunity to call in the walnuts. So the upper head is ideal numbers but on the queen the two center staves are walnut, and somewhat wider. I think the look will be grand.
-- "...in his brain, which is as dry as the remainder biscuit after a voyage, he hath strange places cramm'd with observation, the which he vents in mangled forms." --Shakespeare, "As You Like It"