Ok that make sense, the positions of two numbers were transposed. From your product link, the loco's actual Model number is 6-34735.
This is the parts break down page:
https://www.lionelsupport.com/...de-9c4f-0531cf4233cb
And the 610-1154-130 part number you found does appear to be the correct motor for the 630-4776-200 smoke unit and also matches the information in the separately listed smoke unit:
https://www.lionelsupport.com/...43-b612-3f0be637d12c
Maybe someone else here can confirm all this.