My FSDO says the factory dataplate is fireproof, and suffices for that requirement. The one that they want outside, on the aft tailcone near the left horizontal stab can be written with a sharpie on a piece of masking tape, so long as it's legible. P-touch labels, plastic embossed labels, or even a piece of white paper held on with clear tape would suffice.
Their point is that the external data plate is mainly so an FAA inspector can read it on the ramp. The fireproof, factory data plate is the one the accident investigators will use...not the one in the back.
Tony Baumgard at the North Texas FSDO is my cited source. Lucky Louque of Air Salvage of Dallas is the DAR that reaffirms that stance.
