Hi all, don't post often but lurk a lot. My seat broke last week and I've done a temp fix using some 6inch lap fencing and a couple of small rachet straps. I slid the wood under the frame and used the straps to support it. The seat is now very firm and I sit slightly higher than normal but it will do untill I get round to a proper fix*.
Hope this helps.
*Fixed my passenger window 3 months ago with 2 bits of 4X2, must sort that as well