156 Veloce Clarion (black with green display) Radio Removal

How do I remove this from the dash without bending, breaking or
scratching anything?

I've got the black surround off (no great achievement) but the radio
has refused to budge. There's a metal tab at the top right hand corner
that looks like it might be a latch but it will not move and I don't
want to resort to metal bending just yet! What am I missing?

--
Z
Scotland
Alfa Romeo 156 2.4JTD Veloce Leather
'Oil' be seeing you..
(Email without 'Alfa' in subject are auto-deleted..sorry!)