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Here's a link to a discussion on the Model 39 with post #2 containing a link to Wikipedia information regarding the Model 39.
What's the early history of the Model 39?
The lettering (white ish gold") you describe may be nothing more than personal customization. Photos would help. There was a time when people would add gold coloring to the stamping on guns. This can be cleaned with acetone, tooth brush, and elbow grease. The acetone will not hurt the blue finish.