Elimination of flammable materials. I assume that "leatherette" is a man-made material that feels like leather, but isn't. Such a material could very well be flammable.
Good point. Typically someone who pays that amount of money for a camera (they're selling used for about $1,300 on E-bay) could demand real leather. But if the material supplied by Hasselblad were polyurethane or any similar substance, it would most certainly be removed from the camera for reasons of combustion, not so much for its potential role as fuel, but because of the toxic fumes those substances give off.
The post Apollo 1 materials audit concentrated just as heavily on the toxicity of combustion products as on the propensity of materials to ignite or fuel a fire.