Here is a First Gear 50-3148 1:50 Scale US Forest Service Komatsu D51EX Crawler Dozer. Please see pictures for features of this dozer. Manufacturer: First Gear. Model Number: 50-3148. Category 1: Die-Cast. Category 2: 1:50. Availability: Ships within 1 Business Day! Trainz Product Id: 12322557.