Confirmed by the French Wikipedia and the Dutch version, although both are scarcely sourced. But the truck is indeed called "Type MH 600" in technical documents (fr).
MH 600 and MH 600 BS are separated in this list (fr) and some searches could certainly help to see if there's a difference. It's maybe better to have them as "just" MH 600 meanwhile?

Once more (or should I say as usual?), the model year given by JB sounds like a guess: the SUMB is said here to have been made from 1959 onward while the French army ordered its first models in 1964, which is the usual model year given in the IMCDb. 1964 is not sourced in Wikipedia, but for now I only found the above-mentioned personal site for 1959 as first MY.
The 1968 was certainly first given to some SUMB in the IMCDb (6 out of 25) due to to the 2 trucks rented by Cinema Vehicles (here and here), but as they're described as MB Unimogs, the model year could be as "accurate" as the make...
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Thanks to a source (fr) given by the Dutch Wikipedia, it appears that some civilian models known as UNIC V.I.R.D. (for Véhicule d’Intervention Rapide Diesel / Rapid Intervention Diesel Vehicle) also exist. Maybe some of our SUMB will have to be renamed?