They stopped handing out those letters in 1986. I heard about the deal and rang Craigie, then boss of DCA, to get said letter - I hasten to add I had no desire to carry while flying as part of some BS jungle survival kit but wanted one for general self defence against rascals.
Al informed me that the practice had recently been stopped.
"What dumb c*&t did that?"
"Me actually"
I joined the pistol club instead - bought a really nice FAS .22 target pistol for comps and owned a selection of higher calibre handguns over the years for self protection.
http://www.pilkguns.com/tenp/fas3.jpg