Part code for HVAC unit following a double din conversion

Hi All,

Hoping someone can help. In the summer I removed the single din cage in my 2006 Audi A3 S Line Sportback and replaced it with a double din cage to install a new stereo.

All went well and we have been enjoying the features of the new stereo. I connected the old HVAC unit and all is working fine although the unit can not be reinstalled and flush mounted without doing a further modification which I am told you can do by talking a Dremel drill to the unit!!!!!

So I am looking for a new HVAC unit from a 2006 Audi A3 Sportback without the heated front seat option. I though I found one on ebay and took a chance and brought. The unit fits perfectly but its not compatible having come out of an older model. To save me from another failed purschase does anyone know the part number of such an item? 

Appreciate anyone's help so I can finally finish this little project