Manderson, with respect there’s never been a Chipmunk in Australia registered VH-RCP. All my sources have referred to two RACNSW survivors after the FTA accident (RSQ and RSK), although that’s not to say there weren’t 3. Possibly you’re getting confused with RSP, although that was sold 4 months before the FTA accident.
To try and prove the “coin jammed in the control column saddle mounting” theory, DCA cast around for a similarly configured Chipmunk to FTA (i.e. small rudder/no strakes). As the two(?) survivors had, by this stage, been already fitted with the Aerostructures tapered strakes, they chose AFG. A removable bracket was fitted to limit forward column travel, intending to simulate the restriction caused by the jammed coin. The problem here was that AFG’s owner, at one stage Australian Aerobatic Champion, stated that AFG would recover from a spin “on ailerons alone”.
The trials were inconclusive…