I agree with a previous user in changing the name instead of "The Duke" to "Le Duc" to make it seem more for the Spy rather than the Engineer.

Stats however would be for a more revolver heavy spy:

+15% Damage to Players
-75% Spread after 1st Shot

With very prominent downsides:

-20% Slower Reload
-10% Damage to Buildings
-1 Max Clip Size

Basically making the spy more of a front-line player instead of a supporting character.
(Deciding if I should make the -20% stat Fire Rate or Reload.)

Open to stat suggestions!

And making this the first Engineer and Spy compatible weapon allowing this weapon to keep the name "The Duke" with same positives and instead of -10% damage to buildings to -10% firing speed.
(With a -50% Reserve ammo penalty on engineer.)