I can’t find pictures of VO660 and VO1000 of the New York Central where the bell is visible. They are all from a low angle not showing the top of the hood. I “guess” the bell is somewhere on top of the hood.
Some other RR had the bell at the very front end of the hood but that position is used by the typical VO-front lamp.
Can’t tell you aboiut the NYC but on the PRR theye were under the frame. You will have to find some pictures and don;t be surprised if both locations are ok. Early diesels were all over the map an standardization.
On page 41 of Edson, Vail & Smith’s Diesel Locomotives of the New York Central System, Baldwin S-12 9310 is pictured with the bell clearly visible hung from the frame just behind the steps at the long hood end on the left side of the locomotive (as if you were looking down the hood from the cab). VO660 & VO1000 photos in this book were taken on the other side of the locomotive and no bell was visible.
Thank you. I have that book and looked at the photo (on page 51).
I will not care further for the bell as it is hidden under the frame.