I like the way the colors look together, but I agree that the short sleeves look out of balance with a vest, and worse when the vest is buttoned. I also agree that long sleeves rolled up would look better, but I personally think that look is a bit silly for summer. Going with the theme of "It's summer," I would put the wool vest away until the temperature dips below 70 degrees F or so.

Here's a question for the strict traditionalists: Would a highland gentleman have rolled up his sleeves, or even have appeared in public in shirt sleeves?