I recently purchased a bachmann GE U36B DIESEL ENGINE AND NEED PARTS when i search on this site and plug in the model number it says it can' t be found where do Ineed to look for parts. I' mnot even sure how old this engine is

My wife and I are new to this but we bought a santa fe engine it says 3500 on it and it is missing the couplers but we dont know how to look up the parts for this i've pulled pics up on line but they dont look exactly like mine