This was done for the 72 hour jam of 2017. I think this turned out quite OK. It's not workshop/game quality, but I could see another version using some lights or (advanced, relative to canon/setting) LEDs around the lens.
Here's the model.

First Day (Aug. 4):

• All modeling was completed
• 2 out of 3 base textures completed

Second Day (Aug. 5):

• Team colored textures completed.
• Compilation of .mdl file done
  • Includes .smd reference.
  • Includes .smd physics.
  • Includes idle.smd anim.
• File directories assembled.
  • 5 textures, (2 sets of team colored for neckwear and screen)

Third/Final Day (Aug. 6):

• Readjusted model weights.
• Created replacement for Deus Specs in-game.
  • Team colors work except build_neckwear material (possibly my client's game configuration, model viewer shows correct red and blue skins)
• Altered .qc to get correct skin reference.

Post-Jam Updates:

• Readjusted model weights.

Download it as a replacement for the Deus Specs for Engineer at http://gamebanana.com/skins/156558