Hello, I can't remember ever seeing one single Heuer L5100 with military markings either.
On the other hand I have clear memories of a couple of L5100 by Heuers that seemed either a military derivation of them or military-disguised custom-made versions (very well in the latter case).
They had a bead-blasted case and bracelet, with which none of the L5100 came but easily obtainable on the afterservice market, and a few more distinct features:
- A drab or dark grey coloured dial (photos had a strange light)
- Same colour for time and chrono hands, none of them orange unlike the L5100 series
- The lume-filled triangle hand was swapped and was put on the continuous second sudbial from the 24-hr one, where a standard needle hand was.

Does any regular remember these as well? If they were not military issued they surely looked the part very convincingly.
Cheers.
Fabrizio