The Waltham handwritten records have a number of runs marked with a large script N that, I believe, means nickel plates.
The handwritten records do not include the model year, so one has to be a little careful in reading them. The marking appears first in the book at 1,509,001 to 1,510,000 that was produced April through July in 1881. This was a run of P.S. Bartlett. The gray book lumps this run together with many others as 1879 model mixed PSB and Wm Ellery.
The last run with the script N notation is 2,971,001 to 2,972,000 and is a Home grade 7J run. This run is listed in the gray book as 1877 model.
At a rough guess about 10% of the runs in that range (all models and grades) have the script N. After that the word nickel is written on an angle in the "jeweling" column.
The book I am using has the serial numbers from 1,500,001 to 7,555,000. It begins where the early list reprinted by HOA Press leaves off. A copy is available in the Charles River Museum in Waltham.
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Tom McIntyre
Past President, NAWCC Chapter 174
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