I do like the 1980 cut a lot too. They seem to have a fuller thigh with enough taper but nothing crazy. My samurai s0500's are similar but different. Just look out for 1966 cut specs and look at measurements but yeah nothing is quite the same sadly from what I've found. F380 flathead, sam s0500, and Momotaro tight straight (pretty close?). F380's don't taper as much near the knee, flatheads more rise and tighter in thighs, and the momotaro are close but I haven't soaked because it would be a pain train for how i sized possibly and be closer to the s0500.