I believe this is the best place to get an opinion as they have authenticated my Reagan's over the years. They are quite knowledgable. But my guess is the inscription was not done by the same person and or method as the signature.
good luck,
http://www.reagancollector.com/
![USA [us]](./images/smilies/flag_us.gif)
![USA [us]](./images/smilies/flag_us.gif)
![USA [us]](./images/smilies/flag_us.gif)
![USA [us]](./images/smilies/flag_us.gif)
![USA [us]](./images/smilies/flag_us.gif)
![USA [us]](./images/smilies/flag_us.gif)
![USA [us]](./images/smilies/flag_us.gif)
ps this is their email address which you can also find on their page

CustomerService@reagancollector.com