Hi Catweazle,
My set in the photo came in a crate, unused with toolbox and spare piston rings, valves, plug, etc all encased in grease. Stencilled on end plate that it was inspected by REME FARELF, so looks like it returned home without being issued.
The silencer looks a bit like a cigar case, the flexible exhaust pipe can be made from an old Ferret, Saracen, etc speedo cable outer casing, with the plastic stripped off. We made one in REME workshops once when one came in, silencer was still in stock, would have been late '70's I think.