Dan, you could simply add in the logo schema with this code:
<img itemprop="logo" src="http://www.example.com/logo.png" />
So in your example, you could simply tag it as:
<div class="block-content" itemscope itemtype="http://schema.org/Organization">
<p itemprop="name">SOME ORGANIZATION</p>
<img itemprop="logo" src="http://www.example.com/logo.png" />
<p itemprop="address" itemscope itemtype="http://schema.org/PostalAddress">
<span itemprop="streetAddress">Manufacture Street no 4</span>,
<span itemprop="PostalCode">4556210</span><br />
<span itemprop="addressLocality">CityVille</span>,
<span itemprop="addressCountry">SnippetsLand</span></p>
<hr>
<p itemprop="telephone">0444 330 226</p>
<hr>
<p><a href="mailto:info@snippets.com" itemprop="email">info@snippets.com</a></p>
</div>
I believe that should work for your particular case and it won't actually show the logo and you wouldn't have to mark up the logo separately. Hope that helps.