Unfortunately, merges work one way and can't be undone (been there, done that!!). You will have to create a new profile to re-create Findley-1105's profile. Note that the new profile will have a new ID and any links for Findley-1105 will redirect to Humphries-1468.
You can find the original data for Findley-1105 by clicking the Changes tab for Humphries-1468, locating the edit that says "Merged Findley-1105 into Humphries-1468," and clicking on Findley-1105 to access its changes log. Click the link that says "changes to profile of (I don't know the given name) Findley", then copy and paste the old data into the new profile that you create. The highlighted text is NOT what you will see; I just don't know the given name for that profile!
You may want to add a research note or post a comment to let others know what happened. You should add the note/comment to Humphries-1468 also, for anyone who comes to that profile expecting Findley-1105.
If you need help with these tasks, just let me know!!
corrected ID for Findley-1105 (had Findley-1150)