As far as stuff “walking” from stores goes, the first Courts Martial I attended was for the prosecution of a store man who was stealing stuff to order. He’d had his own keys cut and had access 24/7. He got to do daily PT at Colchester, after which he got to wear his civvies.
Years later I went into a newly opened military supplies shop in Hong Kong. On proud display was a full set of RAF cold weather flying gear, which looked brand new and unused. It had helicopter squadron badges and even better, a personalised “Wings” patch, with the name of a pilot I knew quite well! That type of patch wasn’t issued from stores, they had to be purchased by the individual. I asked the shop owner where he sourced his stuff and he told me he’d bought a consignment of RAF clothing at a car boot sale near London!