Unless you absolutely must have the original back, it may be easier at this point to just refer to your PDF or paper copy of the original return.

If you didn't make a copy of the original before amending the return and you still want to maintain a copy of that original return within Lacerte, the only is to restore it from your backup (if you maintain incremental copies or your backup of the original return hasn't yet been overwritten).

Before you restore the return from the backup, make sure you create a copy of the amended return you are working on so that it doesn't get overwritten when the client is restored.  See this article for the process to follow: https://proconnect.intuit.com/community/help-articles/help/restoring-clients-in-the-lacerte-tax-prog...