Flat Foot Floey said::arated:
But my brother doesn't like flashy ties but a sporty 40s/ 50s style. This collar over lapels thing might be the best idea for him.
Whats the difference between 40s Open Collar shirts and 70s? (except polyester)
Does the collar still have a curve?
Some 70s shirts could work, but not very well, as the collars tend to be too wide up and down. 30s and 40s tend to have longer narrower points. Plus fabric. If you have a good eye, you might be able to find one that works. Keep in mind, the look of the 70s was inspired by the 30s and 40s. But not so well sometimes.
There is a line called Mister California that a lot of guys wear as 50s shirts open collar, but they are from the 70s. (I think)