@slowol
Thanks. Yeah, cheap structural ply 18mm, £37 a sheet. Was going to go with 2 layers till I realised how heavy it is so just added a double-edge for looks and to strengthen. Pot luck with the board quality, the underside has some bad knothole gaps. Edges were better than I expected though with only tiny filling needed. A lot of sanding then Danish oil with wire wool between coats to get the finish.
The missing curved bit hangs underneath as a cable tidy. Chromed legs off the bay do the job but a little lightweight, should have spent more there but desk is wedged into a corner so not a big issue.
Need a plan for the second sheet now….