San Marcos, California-based SD Model Makers delivered three replica models of a 100-foot tractor tug to Nichols Brothers Boat Builders of Freeland, Wash. The 24-inch scale model ship replicated the Nichols Brothers lasts build -- the second of two new 100' x 40' Z-drive ship assist tractor tugs. The tugs are the most technically and environmentally advanced equipment available. "SD Model Makers has provided Nichols with a fine-crafted model of our tractor tug. The attention to detail has captured the vessels complexity and characteristics.