With 1.10 the Deagle was supposed to have the selection for the grip added so that retextures may be applied to the deagles grip. Using every selection that the deagle model currently has, it is no possible to retexture it still.

"bolt",
"camo",
"magazine",
"trigger",
"hammer",
"bullet",
"hide_barrel"

Using all the current selections and applying a new texture to them, no of the selections apply to the deagles grip.