"I am now trying to hunt it down."
Hopefully the "it" mentioned above refers to the locomotive, and NOT the aforementioned family member!
Sorry to hear about the mixup. Best of luck in your efforts to set things straight.
FYI ... You might want to post a photo of the (or similar) loco here so that members on the forum will have a better visual as to anything that might ring a bell at some point in the future.