Here is what came with the machine:  There was also one of those old cushion-type life preservers, on top of a decrepit old piece of plywood, to sit on. Not very civilized. So I cut off the two welded-on bolts holding it in place and put it "aside" to decide how to proceed. I bought a new, simple vinyl seat which, nicely, has a drain hole at the rear, on a well known auction site. Although it has two sets of four (8 mm) mounting bolt holes, the way the loader is made caused me to just use the front pair of the wider set. I measured, cut, drilled, and welded in two 1.25" square tubes to bolt it to. 
While I was at it, I also welded in a couple of bits of scrap angle iron to "protect" my wiring looms on each side. 
The welds are rather nasty looking, since I was burning through the POR-15 primer with my fluxcore wire (read: cheap welder) most of the time, as opposed to grinding down to some nice shiny metal for each weld. Also I had to get used to getting a decent "puddle" in the 1/2" thick steel base and joining it to the square tube stock I used for my brackets. And here is the new seat in place:  |
