What if the parties kept the old nominating system?

[Don Vito Corleone]

Say the parties kept the Presidential nominating system from before 1968, where only a few states actually held primaries, and the nomination was really decided by state leaders at the convention, leading to situations like 1912 where Teddy Roosevelt won the majority of the primary vote but Taft got the nomination, or 1952 where Adlai Stevenson won the Democratic nomination without entering the race until the convention began. Without changing the OTL incumbent President at the start of the primaries, what would each party's primaries look like (you can still have an incumbent President lose if that's what you think would happen under this system)? You can also include people who didn't run in OTL. The only results I'm sure about is that Trump is definitely not nominated in 2016, Mario Cuomo wins in 1992, and Hillary wins in 2008.

[Kingpoleon]

1972: Bayh or Lindsay(D)/Nixon(R)
1976: Udall or Jackson(D)/Ford(R)
1980: Carter(D)/Baker(R)
1984: Askew or Glenn(D)/Reagan(R)
1988: Gephardt(D)/Bush(R)
1992: Tsongas(D)/Bush(R)
1996: Clinton(D)/
2000: Gore(D)/Bush(R)
2004: Clark(D)/Bush(R)
2008: Clinton(D)/Romney(R)
2012: Obama(D)/Pawlenty(R)
2016: Clinton(D)/Bush(R)

[Mr. Smith]

1972: Nixon vs Muskie
1976: Ford vs Church
1980: Carter vs G.H.W. Bush
1984: Reagan vs Mondale
1988: G.H.W. Bush vs Babbitt
1992: G.H.W. Bush vs Cuomo
1996: B. Clinton vs Dole
2000: Gore vs McCain
2004: G.W. Bush vs Kerry
2008: McCain vs H. Clinton
2012: Obama vs Romney
2016: H. Clinton vs Rubio