The consensus after Joshua Logan’s Picnic opened in December ‘55 was that William Holden, who’d turned 37 the previous April, was too old to play Hal Carter, whom original author William Inge had written as a drifter in his mid to late 20s.
But Holden’s Picnic miscasting would have paled alongside another mismatch that mercifully didn’t happen. The film was Arthur Hiller and Paddy Chayefsky’s The Americanization of Emily (‘64), in which Holden had been cast as dog-robber Charley Madison. He wisely pulled out.
James Garner, who had previously been cast as “Bus,” the role that James Coburn ultimately played, took the Madison role.
Holden would have been at least a decade too old to play Madison, who is supposed to be a youngish, slick-operator type (mid 30s — Garner was 35) and certainly not 40ish and world-weary.
Filming on The Americanization of Emily happened in late ‘63 (a hotel party scene was filmed on 11.22.63) and, I believe, early ‘64. A drinker, Holden was 45 at the time and looked every inch of it. He was even looking a bit haggard and baggy-eyed in The Counterfeit Traitor, which was filmed in ‘61 when Holden was 43.
Remember how over-the-hill, creased and saddle-baggy Holden looked in The Wild Bunch, which was filmed in ‘68?
Which other major roles were filled by actors who were clearly too old to play them? Ben Platt in Dear Evan Hansen doesn’t count — too recent.