Hello all: continuing with my (poor) efforts, cabooses (or furgones de cola, as called here) were painted, assembled and tested.
First picture show one caboose along a modified USA Trains outsided braced boxcar. I beleive it stand very high, in fact higher than boxcar.
So I cut an slice on both sides of chassis (second picture)
Now you could compare low and high furgones to boxcar, not only more eye pleasing but also more stable tracking.
Regards from Buenos Aires
Jorge