Marsala is available in many levels of sweetness, with dolce providing the best substitute for cream sherry. Madeira, produced on the Portuguese island of the same name, is another viable substitute. In a pinch, sweet vermouth can also be used successfully in many recipes.
First they are all concrete, just different application methods. Gunite (dry nozzle)is a dry mix where water is added at the nozzle. Shotcrete (wet nozzle) is premixed wet. They both use high air pressure to force the mixture to stick to the wall. Just as if you take a ball of mud and throw it at something, if wants to stick.
A gun stock cradle is an effective way to secure the wood between centers which rotate. This consists of a base member (Wood 2x3) a foot longer than your longest gun stock; it has end members about 6 high attached to the horizontal base. Metal pivots can be affixed to the top area of the vertical members.