Belated thanks to Adriano for linking me through to that post.
Just to say, what I was looking for was actually incredibly simple.
Rather than copying the CSS, HTML or glyph, you just need to add the textual version of the dashicon i.e ‘dashicons-menu’ or ‘dashicons-dashboard’ to the ‘Menu Icon’ field under the ‘Visibility’ box in your CPT settings.
Hope this helps!
I just released a plugin that can help out with this also: https://wordpress.org/plugins/dashicons-cpt/
Dear Hal Gatewood
Great idea, but … we are using dashicons for CPT since 1.6 version (release date: 2014-08-22).
See screenshot from current tested version (1.6.5, release soon): http://iworks.pl/wp-content/uploads/2015/02/types-dashincons-in-custom-post-type.png
Cheers,
Marcin