T26E4:
For building details, you can't beat the Achtung Panzer series. The one you want is issue #3. Tons of drawings on all the external bits -- plus explanations of which belong to which ausf.
Totally agree--there's no better book--or series--than the "Achtung Panzer" series. Everything you need to know is in it.
You can get it from here--- Pz IV