An experienced sno cat mentioned side baskets as an option? How about mounting and some pics on this idea?
Thanks for the step ideas above. May go with adding a receiver. Maybe.
My 1980 1543 had a side mounted basket.
And the 1980 1643 current project came with an open topped box with an expanded metal floor.
But I think the better solution is what Sno-Drifter has on his 543. The open basket (or box) exposes everything to the elements, and to snow kicked up by the tracks. It's open for everyone to see what's there (and potentially walk off with) and lastly, depending on what you put there, it would be an irregular surface to step on if accessing the roof mounted carrier.
We've removed the side box from the 1643 and will be installing a really nice Weatherguard box in that location for the customer. Here's a link:
http://www.weatherguard.com/en/view/Products/Truck Tool Boxes Equipment/Boxes/Underbed Box/660-5-02
On the two __43's I've owned the fuel tank has been mounted outside the cab. (I think that may be a worthwhile mod for your consideration for the extra interior space.) Tucker welds two "outriggers" to the top of the frame and bolts the tank to those, and to the cab. The ends of the outriggers are cut on a 45º angle and on the outside end taper from being longer on top to shorter on the bottom, and the opposite on the inside end so they protrude minimally in terms of the rear seats. The open ends are capped with welded plates. Our intention is to make two similar outriggers, from the same size square tubing, and mount them the same way. The Weatherguard box will be bolted to the outriggers.