Sam Whiskey (1969) on Netflix

At the end of the Civil War, Sam Whiskey (Burt Reynolds) is seduced away from his career as a gambler by the lovely Laura Breckenridge (Angie Dickinson). She wants him to help her recover a quarter of a million dollars worth of gold bars which her late husband stole. The gold is aboard a sunken river boat in the River Platte in Colorado and must be recovered and restored to Denver Mint before the theft is discovered - which could destroy Laura's family name. Sam agrees to do the job for $20,000 and teams up with a local blacksmith and a buddy from the war. The team heads for the Platte, unaware that they are being followed by an outlaw who wants the gold for himself. Using a home-made diving helmet that will allow Sam to go beneath the river; but after the heroes retrieve the loot, the outlaw steals it from them. With some interesting weaponry, Sam manages to recover the gold and with his cohort rejoins Laura in Denver where he poses as a government inspector, enters the mint, and "accidentally" damages a bust of George Washington. He insists upon having it repaired and takes it back to his blacksmith friend, where the gold is recast into the shape of the bronze bust. When outlaw Rick Davis catches up with the trio, he mistakenly steals the original bust. Sam and company gain entrance to the mint and there recast the bust back into gold bars. The next morning Laura rewards the men with the promised $20,000 and Sam with her heart.