Well, I can say with high confidence that they are not in Charges, so it is NOT the case the case that they are 'should' be paid indirectly by application of the percentage people overheads.
There is an argument for saying that they are in People if you take the statement in the Guidance Notes as a 'persuasive' argument, namely that "The intention is that amounts paid in the Shorter SCC" (for People) " would cover all the items listed in the full SCC." and that if you then look in the full SCC, People 13(a) might be applicable.
However, from what you say, it seems that they are almost certainly Equipment i.e. "items provided by the Contractor and used by him to Provide the Works and ..." . I could quote the definition of 'to Provide the Works', but I will leave you to do that.
There is an argument for saying that they are in People if you take the statement in the Guidance Notes as a 'persuasive' argument, namely that "The intention is that amounts paid in the Shorter SCC" (for People) " would cover all the items listed in the full SCC." and that if you then look in the full SCC, People 13(a) might be applicable.
However, from what you say, it seems that they are almost certainly Equipment i.e. "items provided by the Contractor and used by him to Provide the Works and ..." . I could quote the definition of 'to Provide the Works', but I will leave you to do that.