Hi martin, I have one set of it and i don't think the material is different with Normal one. Maybe slightly thicker but not much. and i don't know about unique kepi cap for tanker, any info ?
About the epaulettes, Tanker shirt is different with normal. It have 2 plates, one for putting the rank on it another one which can't button open, i think that's for placing the rolled hat or the beret.