Yes, I would agree there is something not right with the letter/company.
I cannot find a trace of Mason & Pringle, or Harvey Black. Given the business they claim to be they should be registered somewhere.
I'm not sure where to go from here though as the Company, even if it does exist, hasn't provided an address of an actual office (just a PO Bos number).
I've raised a complaint with the police, but are they going to interested? how long will they take to look into it?
any ideas would be much appreciated!