good glad you found some of my waffle useful,rust is worth study wherever you see it,notice how rust spots leave faint streaks of that tan orange colour running downwards on top of the paint,ie the residue washed with rain,and by the way your idler should'nt move the arm should be fixed to create the correct tension,gravel will make problems,get between tracks and running gear and throwing them,a real tank would'nt face such ground in other words the size of your gravel x16 getting thrown up into the tracks,try short grass and dusty or muddy areas,that will weather your tracks,believe it or not the Tigerfibel(manual)told crews to avoid long tall grass because of build up throwing tracks or creating over tension that meant they had to be cut off by blow torch
