I visited the interior of one of those Pollution Control DC3s at Coventry they contained two foot six diameter tanks mounted crossways. The same day I crawled round in a Shackleton. Plus sat in other aircraft took flights in a DC3 & a my favourite plane to fly in the Dragon Rapied. Can’t remember the name but the aircraft at 57 seconds had been moved into a hanger for refurbishment. The seats were out so plenty of room to swing my arms around inside. The DC6 often flew out around midnight. Usually flew out over our house about four miles out from the runway. Lovely sound. Reminded me of living near what has become BHX when I could hear aircraft running the engines & checking the mags before takeoff.