"My mom's old bed repurposed as a sideboard. Cabinet doors on both ends for dish storage." This is an amazing idea! So many old beds underused now that king size is preferred. Perhaps do something similar only, use it for a bathroom sink. I love old furniture as vanities but it just kills me thinking of a nice sideboard being cut up. This way you cut the new materials only and mount the old ones with screws. By setting hb up high there will be room for mirror.