Friday afternoon, kids off school so I have a free afternoon. Called in at the local woodyard on the way home and set to it. Here's the results

One traditional 9mm ply topped, softwood framed board. 4 foot wide and 46cm deep. Why the mixed units? - it was easier to work out the length of the side members that way as the framing timber was 2cm wide

Might have a play putting things on tonight when the kids are in bed - SWMBO is on a girlie night out