Years ago, I used the declarations of intention from Hamilton County, Ohio. The courthouse has had several fires. When I saw the declaration of intention for my ancestor it looked a little unusual. When I saw the declaration after his I realized the the signatures were in the same handwriting as the document and were the same handwriting from one document to another.
Turned out (when I read the prefatory material on the microfilm) that the declarations of intent I was using were transcriptions made from the damaged original after one of the fires.