I list a couple Model 60-4s with BRN through BRU serial numbers that shipped in 1994.
At BRR I would bet a dollar to a hole in a doughnut the hammer and trigger are not flash chromed. I haven't seen one after BRN with the flash chromed parts.
Here's my BND with flash chromed parts, shipped in August 1992, and my BSP without flash chromed parts, shipped in March 1995.
The serial numbers I show in the database through this era were shipped in alphabetical order except the Performance Center Model 60-7 ET COMP with its PCQ and PCR serial numbers, which interrupted the flow between BKP and BKL in summer 1993.
Keep in mind the SCSW, 4th Ed., could only publish the information available at the time. We've learned a lot since 2016.