Bit of a confusing one this. We spotted the top image on Twitter recently,. with a link to the shirt section of the John Simons website. Thing is, we're not sure if the paisley pop-over shirt by John Simons on that page is the same one!
Madras shirts are like buses, you wait for one, then several come along. So if the Beams Plus offering didn't float your boat, you might want to have a look at this Gitman Vintage Archive Madras Check Shirt.