The drop tanks are a interesting observation. Spitfire seats, where made of compressed paper and soaked in resin too. Not all seats where resin/paper but, it was more common. Often the seat was a brown color. For awhile folks thought they where made of Bakelite but, this is not the case. There has been another word that escapes me but, the current thinking is that proper verbage is resin soaked paper seats.Not all Spitfires had the seat some used metal. But, I wonder if the process for the seat and the tanks are one in the same.