I think the sizes could also be written by the Bundesheer. These uniforms were repeatedly reissued to soldiers, which would mean needing to have readable sizes for the depot clerks. To me, the ones that mimic the BH's measurement system are more likely from BH and not shops. I would think surplus shops would more likely just write "48" or "M". Certainly I've seen ones resold to the US that have US chest measurements.