I don't believe SC's nightdress was tested for GSR? But let's assume it was, given SC sustained 2 contact gsw's and was in an environment where the rifle was discharged numerous times ie 8 gsw's June it wouldn't really tell us much since GSR forms a cloud upon discharge and deposits indiscriminately on anything in the vicinity.
In terms of MF's claims re waxy substance and gun oil afaik these are not established scientific tests routinely used by independent forensic service providers? Which begs the question why MF would expect to find such debris when the rest of the forensic science community wouldn't be looking?
List of UK based forensic service providers. Afaik the only reliable test used to determine whether someone has recently discharged a firearm is a test for GSR.
https://www.justicedirectory.co.uk/directory/forensic-services/In terms of whether SC's nightdress was free from victims' blood, other than her own, how would we know when the type of tests used in 85/86 required stains of a certain size and quality? If the nightdress hadn't been destroyed by Essex Police against all protocols it could be tested using DNA tests.