ED - Superb prototype photos. As you noted, wrecking cranes all traveled with boom cars, to avoid poking holes in high cars. Your Union Pacific crane has a cut down passenger car as it's boom car. Generally, the "wreck train" was an assemblage of old cars which would include the boom car which would carry perhaps blocks of wood, auxiliary trucks and tools. Additionally there might be a reassigned tender for fuel and water, a box car for tools and blocks, a dining car, with picnic tables to feed the crew, plus a kitchen, and finally, a dormitory car, for crew members to grab some sleep. The Burlington Route employed cabooses (waycars) on their wrecking outfits in the last years. The Burlington kept there derricks "hot", with live steam from roundhouse or shop sources, so that they would be ready to go at a moments notice. A fire would be built in the firebox en-route.
One quite appealing element to the Overland crane is that it is self propelled, just like the prototype. Again, your model is excellent!
