Thank you for posting the link to that brochure! From the drawings of the locomotive trucks (e.g. the one on page 7), it looks as if the ends of the truck frame DO taper over the axles, with the upper edge slanting downward (though the lower edge seems to be horizontal). Intuitively this makes sense from a weight vs needed strength point of view, but I don't think I had seen anything quite like it before!
Sorry, I guess I'm not knowledgeable enough to appreciate the mufflers! … Both EMD 710-engined locomotives and GE FDL-engined locomotives built for use in countries (UK, Australia) with stricter noise regulations than the U.S. have been built with mufflers. In the Australian types I am familiar with, the muffler extends more or less the whole length of the engine compartment, with the result that the EMD units have the final exhaust stack at the end of the engine AWAY from the generator, and the GE units have the external exhaust stack AT the generator end: very weird-looking to an American eye!