Hi James,
We previously had trouble with the icons showing up as letters on WAMP packages, but it appears that your problem is more specific.
If you can provide any additional details about your server setup, that would be great.
Can you also list the CBOX theme version are you using? You can find this by logging into the WP admin dashboard, then navigating to “Appearance”.
Also, if you know how to use the developer console in your web browser, can you also list if there are any errors in your console?
A quick guide to use Firefox’s console can be found in another reply I made here:
https://commonsinabox.org/groups/help-support/forum/topic/minor-issues-notes/page/2/#post-1254