Pretty good work.
For the textures, esp. the tank I'd go and get some images from a real tank, topview, sides and maybe front and back view of it, all you can get. Then do some copy paste of structures and surfaces until the stuff covers your UV map nicely.
For this you NEED to work with Layers, forget Pain(t).
For an easy solution get Artweaver that is a pretty good photoshop substitute, as long as the task is simple. Or get "the gimp", a fullfledged photoshop replacement, but needs more time to learn. (Both free)
So, when you have Layers then you can use the UV Template layer with 50% alpha and align the graphics on the other layers to it.
For the textures, esp. the tank I'd go and get some images from a real tank, topview, sides and maybe front and back view of it, all you can get. Then do some copy paste of structures and surfaces until the stuff covers your UV map nicely.
For this you NEED to work with Layers, forget Pain(t).
For an easy solution get Artweaver that is a pretty good photoshop substitute, as long as the task is simple. Or get "the gimp", a fullfledged photoshop replacement, but needs more time to learn. (Both free)
So, when you have Layers then you can use the UV Template layer with 50% alpha and align the graphics on the other layers to it.