Adding icons with Fontello

I’ve added two new icons to the “default widget option values:”

'goodreads'              => '',
'amazon'                 => '',

and also updated the “social profile choices:”

'goodreads' => array(
'label'   => __( 'Goodreads URI', 'ssiw' ),
'pattern' => '<li class="social-goodreads"><a href="%s" %s>?</a></li>',
),

'amazon' => array(
'label'   => __( 'Amazon URI', 'ssiw' ),
'pattern' => '<li class="social-amazon"><a href="%s" %s></a></li>',
),

I selected all the existing icons on the fontcello site, and assigned the same codes. I added my two new desired icons, and made sure their codes were different. I downloaded the new files and replaced the ones in the plugin.

The two new icons are now in the config.json file (along with the original ones):

{
      "uid": "2f85c90013c0af641d18b167ec93d165",
      "css": "amazon",
      "code": 59407,
      "src": "zocial"
    }

and

{
      "uid": "9755f76110ae4d12ac5f9466c9152031",
      "css": "book",
      "code": 59648,
      "src": "fontawesome"
    },

The font files are also all updated, but my new icons still show as blank gray squares. What else am I missing?

(the unicode won’t paste in right, but they are all correct)

Thank you,
Jessica

https://www.ads-software.com/plugins/simple-social-icons/