Yeh cheers for that. Low mount winch, only a 12,000 lb jobbie, not winch challenge stylee lol I'm making an other piece of steel box to fit inside the chassis rails with welded on nuts. So there'll be 6 big ass bolts holding the tray bit on, same as the old pig tail ones. The box bit in the chassis will have the recovery swivels mounted in them and then bolted on the outside of the chassis too. The under side of the tray will be cut some more for drainage.
Chassis rails are a bit surface rusty and on the ever increasing list of to doooos :/
Mig welder.
My last winch bumper was 6mm and seemed to do ok but will look at some more strengthning on your advice, ta.
I'm using stainless bolts.