Most visitors online was 1660 , on 12 Dec 2020
I am pretty sure some of the Am'n grade examples were available in 16 jewel and maybe all were 16 jewel The chronographs were available with split seconds and accumulator also. Those might have additional jeweling. I am on the road right now and can't check. I am sure Jerry T can tell you.
I should not do this when I am too tired. I just now realized what you were saying and noticed we were talking about 1874 models, not 1884 models.I just wonder whether Waltham originally manufactured these Riversides from the 1,787,200 thru to 1,787,700 serial runs just as normal 11 or 13 jewel watches and then the Chronograph fittings were fitted later by specific Jewelers'? Also, if they were made only for the English market, as they have not the Waltham or American Watch Co name on them, just plain with serial number and the patent date for the Chrono mechanism,? The hand written ledger has them as just watches with plain jeweling and with no reference to them being Chronographs.