Ted, Mael is wearing a vest made up of about 3-inch squares of various bits of tartan, more or less like what you were asking about, only straight across, not on the bias. It's a rather bold look, in my opinion - I'm not sure I'd wear it with a tartan kilt beyond what Cloves suggests.

At the top of the thread you asked about what other vests men would wear. Rarely have a seen a gentleman in a patchwork or quilted vest. Usually they are solid. Sometimes they are brocade - often seen in western wear and what you might call festival formal wear (such as at high-school proms, New Year's Eve). In another thread, we were commenting on a yellow-and-cream brocade vest under a green jacket.

Regards,
Rex.