The recoil you need was used on the Mercury equivalents of the Wizards -- the KE7, KF7, KG7, and KH7 models. I would try emailing the following gents who sell parts and complete vintage outboards.
Doug Penn (Douglas.Penn@gmail.com) -- I use Doug for most of my parts needs. He is very reasonable, ships quickly, and is a super nice guy.
Bob Grubb (Bob@grubb.com) - Bob is trying to fully retire and wants to get rid of all his parts/motors, and I bet he would have a recoil from one of the above models. Ideally he wants to sell off his parts in a large lot, but he might be willing to help you out.
If this doesn't work, post a free wanted ad on the AOMCI.org "Webvertize" page.
Thanks for the leads JP, but the recoils will only fit those models I mentioned and KG9. I doubt anyone would rip apart a KG9 for this. Merc recoils are inset (flush) to the gas tanks (with 3 bolts) where Wizards set on top of the gas tank.
Sorry on the models....it can be confusing with the Mercury Wizards....they don't all equate back to the Mercury powerheads they are based on. I would still recommend giving Doug or Bob a holler. If any guys have a KG9 for parts, they will. If you haven't already done so, try a wanted ad on the AOMCI.org website (see Webvertize link).