The other thing that can make tail draggers more difficult is the center of gravity position in relation to the wheels. In most scale models, including war-birds, the cg is located only slightly behind the main gear. This contributes to the scale appearance, but makes it harder to keep the tail wheel on the ground at the beginning of the takeoff roll. Once the tail wheel is off the ground, if there isn't sufficient air speed over the rudder, control is lost, and you ground loop. If the wheels are close to the CG, it also makes it easier to nose over. This will be aggravated if the plane is nose heavy. A rough runway will also make it more difficult. If there is anyway to move your main gear forward a little (an inch or so), you will see an improvement in ground handling, and better resistance to nose overs.

Holding up elevator at the beginning of the takeoff roll is absolutely necessary. Releasing it as the plane gains speed is the trick to prevent the plane climbing out too steeply and stalling.

Some tail draggers are easy, some are hard. Personnally I prefer tail draggers cause they're easier to set up, and nose gear is heavy. You just have to get used to them.