Lost Tab Icon on Upgrade to Kibana 4.6.1

I had a custom tab icon and .svg logo in the top right hand of my Kibana UI. However after upgrading from 4.5.x to 4.6.1, that custom badging no longer appears and is replaced by the defaults.

I've followed the same steps necessary in prior versions;

  1. upload the custom icons to $./optimize/bundles/src/ui/public/images/
  2. remove & reinstall a plugin to force Kibana to optimize & cache browser bundles
  3. restart Kibana

And still the generic badging appears.

Has anyone successfully customized the badging in Kibana 4.6.1?