I am currently building a GP38 High Hood from an Atlas GP40 chassis. I ordered my parts from Atlas and m.b. klein.
Atlas parts
Gp38 High Hood Cab
GP38 High Hood Nose Body with Dynamic Brakes
Bell and Bracket
Snowplow
Rotary Beacon
Mu Cable Set
Ditch lights
Mb Klien aka Modeltrainstuff.com
Blma Emd Cut lever
Blma Windsheild wipers
Blma Trainline hoses
Microscale Decals NS 1987 to 2002 diesel engines