Hi John,
A slight air leak will cause a reed to soound sharp, but,if you covered the hole with wax, then you have cured that problem. I would question on thing, is this reed plate one of the ones laying flat, or is it on the "solder block" standing up? The reason I ask is, if it one laying flat, make sure that you resealed the wax all the way aroounf it. Sometimes, when removing one of the reeds laying flat, the wax on the back end of the plate will come off with the reed plate, or be displaced enough to cause a slight air leak. This leak will cause the reed to sound slightly sharp. Hope this helps.
Jude