If the Lock is the Model 850 from 1929, the Catalog cites the Key Blank for the 5 pin tumbler lock as a Yale No. 8.

Not having much luck cross-referencing a Yale No. 8 to a present day Key Blank for Yale or an off-the shelf After-Market Blank, i.e., an ILCO After-Market Blank.

Does anyone have insight as to a readily available Key-Blank and Key Blank Number? Another Fella told me that it would be a Tale "P8", but I can't seem to find.

Thanks Again.