Yes. It's set in appearance.2da, the values for the modelb/texb columns. In TSL they replaced the class clothes with the commoner clothes models. Have a look at K1's appearance.2da and you'll see the values you should use and change the appropriate rows for your player's head (or all player's heads). The three different classes use the three different sizes, small, medium, and large. Soldier is large (PMBBL/PFBBL), Scout is medium (PMBBM/PFBBM), Scoundrel is small (PMBBS/PFBBS).
You should only need to put DH's texture in the Override folder.