A seat is a great 'tool' for spotting and culling from. I tried one of the £99 specials you find on the web and it was too low for me and a little wobbly. But I had it now!
Two 4" bits of angle steel to raise the bar height and bolting the shooting bar to the holes at the top of the seat instead of the bottom holes sorted it - see photo.
Great height now and more stable. I couldn't justify the cost of another seat from my usual UK built to supplier so £99 and some time in the garage did the business.
I also upgraded the bolts a size up from M6 to M8 (from memory) which fitted the existing holes (B&Q £15 lot for stainless), some pipe lag, duct tape and left over hammerite paint finished it off.
Off cut of foam found in garage saves the back. The remaining angle section was tacked under the seat and across back to take straps to tree and make rigid.
Might be a useful tip for others. Made a "cheap" seat into a great piece of kit that should endure the weather for a wee while.