No doubt it's a Bren carrier. Oversea's tank regiment was specials. Mainly used as counter insurgencies forces, specific terrain (desert, jungle, mountain or marsh). This "mutation" start with Indochina war when troops use what they found to try to do the job.
Result : they use specific tools for each mission. I could add several kind of unit for the Indochina period but you already have similar unit in the oob (062 Spahi Sqdn or 004 Chasseur Sqdn). A quick copy/past name change
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I have just made the REC Indochina unit because it was fun, exotic, romantic and a good view on the "scratch built" units mentality in this times
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