Many old time products get "improved" by bean counters in a company. Often accountants ruin a company by turning a good product bad.
As a side note I was doing some research several years ago, lookin' at lists of groceries that the Commader of Ft. Schnelling in Minnesota ordered from St. Louey in the 1820's, one was steak sauce. Well the bottle of A-1 in the icebox did not say when the company was founded, so I took them at there word and called the 800# for questions about the product, was given the company historian for the company that owns the A-1 name and found out it dates to the 1700's and was imported from England in at least the 1760's and they claim to use the original formula.
MWW I bet it is anchovies they use, it is in many products, a hazard to those with fish allergies, the use of fish for such is interesting and somewhat nauseatin' at times if you study the whole story, there have been worse things used even today in some parts of the world, at least the anchovies are not fermented.
Study the solurum sauce the Romans used, fish and salt and it took at least a year to make by a drip method.
Bet Forty Rod ran into some similar stuff in SE Asia.