I have been doing some quick research on the Reading SD-45s. I have an opportunity to purchase one. I already have one Bachmann Spectrum SD-45 #7603. The second I can purchase for a price I can’t refuse is also 7603. There is an outside chance I could get 7602. In looking at a couple of websites I only found roster numbers from 7600 to 7605. Did Reading only have six units? Also did they MU them together or with other locomotives?