At last I've finished the deck for the lakehouse. I'm quite pleased with the weathered look to the boards - the grey and yellow seem to go well together.
The floor installed - it was a fight but I won :))
I ended up using Aleene's Tacky Glue (thanks for the suggestion, ladies) and weighting it down with heavy stuff (bags of cutlery is very effective!) on a thick oven tray, as well as clamping the front edge under a metal ruler. I kept pushing the back edge down with my fingers through the drying process, every ten minutes for an hour.
It has very slight ripples, but nothing that well-placed furniture and rugs can't cover ;)
Next time I use this veneer I'll do the flooring first, before building the kit. Then I'll be able to get at all the edges to flatten them properly. The attic in this house was particularly difficult to get the floor into the corners.
Now my little supervisors are asking 'where are the stairs?'.