http://www.ebay.co.uk/itm/Fishing-box-seats-made-to-measure?item=280849449937&cmd=ViewItem&_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D3%26po%3DLVI%26ps%3D63%26clkid%3D7272462546639689370

I have a brilo box which I love but the seat just aint comfy enough until now. I sent off an old seat for mine (having bought a new brilo one which was not much comfier) and two weeks later new refurbished seat tuned up.

It is very comfy, looks great (I went for black with the red piping), fitted perfectly (all brackets were reattached) and shows great workmanship.

He can make a seat to fit or refurbish an existing one. There is another design (look at ‘see other items’).

I have no affiliation with the guy that does this, just suitably impressed to recommend it to others.