Porter Bell and Bracket

Can any of you Porter Locomotive fans out there tell me if Porter made bells smaller than 12" in diameter? I have access to a Porter bell bracket with a 12" bell and the mounting bolts are 5 1/2" center to center. I am planning to make foundry patterns for a Porter style bell and bracket for a locomotive where the mounting holes are 4 1/2" center to center possibly indicating a smaller bell and bracket was on this locomotive. I know that I could make a smaller bell and bracket, but would it be prototypical? I have plans and dimensions for Porter bell and brackets but the smallest they indicate are for a 12" bell.

Any feedback?

Bernie