Saw yours previosly (sp?) I got one at Lowes $27 I am using a 1 gal paint thinner can on its side for fuel in the lower section.
Its on its side over the axle ---can't put but 3 quarts in the can to keep the level below the cap but didn't have to cut the tray.
I have a wooden partition between the can & the battery & pump on the front side to isolate fuel/ sparks.