I don't have precise information about the timing of the sale, but Mercury Racings' fate was sealed the day the Kiekhaefer family sold out to Brunswick. The big, bad evil corporation will do what it must do to survive, which is generate a return on investment for its shareholder. Can't blame it for cutting losses on what became a boutique segment of the business (i.e. a shrinking customer base unwilling to pay the prices needed for that segment to stay viable).
Plenty of targets available to point fingers at.... The customer who wants a dollar song for a nickel, the Kiekhaefer family who want to monetize dads/grandpas vision, and Brunswick who want to turn a reputation into cash.
The first generation makes it, the second generation enjoys it, and the third generation blows it.....