We've been asked to work on a tricky project to convert an org that is currently in operation to use multi-currency (Not advanced MC). They have a multi-national org that has been filling in Oppty's and other custom objects with currency info for about 18 months wihtout indicating which currency they are using. We know that when multi-currency is turned on, all currency will be reflected as corp currency.  Has any done the work to "re-convert" the currencies back to the respective national currencies that the reps thought they were working in? Thanks for any tips or gotcha's.