Re: Mayfly Drake Fly Swap
Cool AJ. If you're looking for patterns I think the "Danica"mayfly (Ephemera danica) at about a size 12, is common big mayfly in Sweden (and much of Europe including Great Britain). Although a bit smaller than our eastern green drake, it looks to be quite similar in its nymph, dun, and spinner stages and is in the same mayfly genus (Ephemera).
You can find tons of patterns for it doing the google or come up with your own version