WOW, That's an AWESOME Find !!
Many THANKS for sharing this with us, it's truly a unique piece. I too love US Govt., Federal L/E issue handguns, along with a few longarms if they fit into the overall mix. Although they do prove a very interesting research progect, they don't appear on the market much anymore. I still lament not grabbing a few of the 1980's era Model 686/CS, as mfg'd on contract for US Customs Agents & Officers. The last unusual M-49's I recall, were the MI State Police, 2 Tone, & a Saudi Arabian contract piece, complete w/ Saudi crest on it's side-plate. YOUR example though is an extremely rare, perhaps 1 of just a very few still available. BTW, as for the holster, I used to come across these all the time when browsing through the used holster bin at my local L/E supply & gun shop. I still use one with my alloy M-642 "LS" when I feel that gun's appropriate for what I'll be doing or going. THANKS again for sharing.
Best, dpast32