Each Historic Preservation Zone dates to a different period and has a distinct style or styles. The city has published design standards for each. The historic period fro Armory Park is 1860s to 1945. Below are links to guidelines and standards to help design a suitable project.
Here is the link to the files related to the draft Design Guidelines updates: https://drive.google.com/open?id=1Sgbt64-YA6t99Hj2fcuqQ3Awdvh9iMG1.
The latest version is here: https://drive.google.com/file/d/1Q1eCbYrOmTG__XeeXx1tWx8iWj7J4KSt/view?usp=sharing