So I just learned that Patrice Alexsandre, who played Saint-Just in Saint-Just et la Force des choses (pictured top-left) ALSO played Dorian in a 1977 adaptation of The Picture of Dorian Gray (pictured 2nd from the left).
But it gets even better. Remember Denis Manuel , who played Saint-Just in La terreur et la virtu (pictured fourth from the left)? He plays Basil Hallward in this 1977 adaptation of The Picture of Dorian Gray (pictured third from the left)!
So there you have it, right at the bottom there. Two Saint-Justs on one screen. With homoerotic tension no doubt.