Chuck,
There is info in the stock books about Drams of Shot unsed in patterning.
Please refer to page 866 of TPS. It shows a photo of a near full stock book page from 1928. unfourtunately the top neader columns are not in the photo, but it does go all the way to the side. It shows a column with a date in it even ferther than the one you mention. But, it shows the same fractional number after patterning info. In this case, mostly 2-1/2 and 3. But, on this page all of the letters do have "dr." or drs. written after it.
The couple other examples of stock book pages in TPS are photocopies, just like the ones you use, which cut off those last columns. Page 866 is the only actual Photo of a full page in TPS.
Also,
See this attached photo of a stock book from 1913. I took this photo while I was at Remington. It is the one stock book that is on display in their museum. This shows the column headers. The column that you are referring to is labeled "Remarks" in this book. And they same info we speal of is listed here as well. With "Drs" after it. And it looks like they note that 7/8 oz of shot was used in most cases (in a few going as high as 1-1/4 oz) right before the drams of powder.
Parker Trip 142.jpg
The 1928 example in TPS also shows the oz. of shot and drams. And also those dates. One above that info and then another date with a large "X". Looks like there was a variation in header titles from 1913 to 1928.