Sorry but this is not true!
To be TRE and SFE as well, you should be with valid: ATPL,valid type rating and clas 1 medical (active pilot) This is according CAA regulations!
I have similar problem. According to JAR FCL 1.455 to work as SFE I should have valid type rating on the applicable aeroplane type. What is than diference betwen TRE and SFE? I wiil thank to any serious explanation.