Dear TRC and all. You (TRC) are of course correct about AM having the CAA Major Mod approval for the Casey Heater. I was in the D.O. at the time this mod got CAAed and I can still see the drawings now! (in my head anyway). I'm sure Gama have dropped this along with nearly all the other Mods done by the AM Group over the years. This leaves the mod and continued airworthiness matters, including supply of spares and maintenance data unsupported. Unless you can find some old stock of (certified) spares I think this mod is now dead in the water. You might find a DOA that wants to take charge of the mod under EASA but probably more trouble than it is worth.............