It is known from works on Waltham such as Moore's Timing a Century (1944 or so), that Waltham was still using handfitting for RRG watches into 1924. I believe Tom M. also provided similar info from an account he heard first hand (something about being unable to fill an order because master watchmakers were not available).
I can tell you that based on the technical information I have collected on over 200 Hamilton 16s from 1896 onward, that the parts were interchangeable down to the escapements. Escape wheels were interchangeable as were pallet forks with the exception of matching which is still required in the lever escapement today (since pallet jewels are moveable). Jewel sinks, jewel chatons, wheels, pinions and such all interchange. Parts from a 990 can be interchanged with parts from a 974/976/972 with the exception of arbors/pinions that ran on capped jewels.
I have documented elsewhere that from the start Hamilton standardized parts in a manner similar to the manufacturer's engineering catalogs of today. Hamilton designed models using parts already in inventory. They did not make a new screw, pinon, wheel or escape wheel for each new 16s caliber (other than brass EW vs steel).
This approach was very different from that in vogue in the late 19th cent where factories such as Hampden and Waltham had multiple production lines running to accommodate that various grades. This includes tooling libraries, machines, workers.
This should not be a surprise. Rood ,Cain and Perry took over New York Watch, turned it into Hampden and later sold Hampden in order to start a new venture. They were from Springfield Ma and were well aware of the advances made by the Singer Sewing Machine co and the state of the art of such companies such as Starret. They would have been very familiar with the problems of parts and inventory control, tooling, and multiple models by direct experience at Hampden and by following events at Waltham.
Remember, the screw micrometer was only mass produced in the late 19th century. The field of metrology was barely invented.
The period between 1888 and 1892 is a little unclear regarding Rood, Cain and Perry. We do know that Rood and Dueber visited the Aurora factory together and that when Rood decided he wanted the rest of his money from the Hampden sale so he could purchase Aurora, Dueber tried some financial machinations that ultimately failed. Cain and Rood went took over Aurora after Cain closed out the Lancaster Watch Company.
I have seen no documentation of the purpose of these latter moves, nor of what Perry was up to. Cain and Rood did move machinery and workers from Aurora. But the 16s Hamiltons required all new tooling and Rood decided against a winding design that would have allowed the use of Dueber cases (the often-discussed positive detent).
I am impressed by their ability to apply high standards of consistency of quality control 10 years before the Student's T-test was invented (an important statistical tool used in probability) which is the basis of lot testing used in production today. How they controlled tooling consistency is a marvel. The FACT they did control tooling and quality to this extent makes them stand in manufacturing.
I have taken parts from a 974 and exchanged them with 990 parts. I have taken parts from a 1906 992 and exchanged them with parts from a 1921 992. Same with a 974 across decades. The Hamilton 978 was simply a 3 pos adjusted 974. The 972 was a fully adjusted 974. Essentially, all 16s Hamiltons are derivatives of the 974 and the parts interchanged.
This would have been of high importance to Perry who was the "salesman"; which meant he had direct interactions with the stores and knew the issues related to parts availability in a sale sector where service was paramount. Compare the complete finish of an 1884 Hampden Perry (one of their highest grades) to that of the 1898 974. In the former, unseen parts are left unfinished. In the latter, the pallet fork, screws are highly finished. I suspect Perry had a say in this.
Rood, Cain and Perry all come from Hampden County MA. I have not yet been able to establish their relationships prior to New York Watch (ca 1874). But from 1874 onward they were a management team.
It is my hypothesis that they sold Hampden with the intent of designing a completely new way to produce watches. This is certainly what they told reporters from the journals of the day. I think they were watchmakers in personality; very intentional. I am hoping that correspondence survives that sheds light on what they were doing as a group between 1886 and 1892. And certainly, they were in no rush to get product "out the door" since that only started in 1895.
In essence, I think Cain Rood and Perry foreshadowed the approach the Japanese took toward the steel industry after theirs was destroyed. Rather than use old technology and processes. use the most advanced techniques and processes available. Established manufactories such as Waltham and Bethlehem Steel had too much invested in physical plant to tear it all down and start over. They had to "make do" with incremental improvements while maintaining sales.
While Elgin and Illinois had the same issues, it seems they managed the transition better. But they were still at a disadvantage compared to Hamilton by trying to be all things to all people. It seems the motto of Hamilton should have bee "simplify".
Other than the ill fated 976, Hamilton never made a "cheap" 16 size watch. In fact, if I were a retailer interested in establishing a reputation in my community, I would have purchased 974s and adjusted them before sale.
