From 1974-76, Cooper played in 350 of 486 games, totaled 1,270 plate appearances & put up 4.6 WAR, or .0036 WAR/PA. Let's say he had been the full time starter since 1972 & averaged 600 PAs per season through 1976 with that same .0036 WAR/PA, that essentially would haved added about 6 WAR to his career total. The average HOF 1B has a career WAR of 66.9, a peak 7 year WAR of 42.7 & a JAWS (50/50 career/peak split) of 54.8. Even if you add those extra 6 WAR, Cooper comes in at 42 career, 30 peak & 36 JAWS which still falls well short of other recent 1B like Keith Hernandez (60.3/41.3/50.8), John Olerud (58.1/39.0/48.6), Will Clark (56.5/36.1/46.3), Fred McGriff (52.6/36.0/44.3), Mark Grace (46.4/29.7/38.0) or Don Mattingly (42.4/35.7/39.1).