Actually that's not all that hard, though I've been making lit signs for way too long. The cabinet outsides will have to be made from flat sheet metal and the lettering cut out (router or water jet) and then wrapped around a welded aluminum (or steel) frame. A sheet metal roller (slip roll in the USA) will be best tool for that. The hardest part will be to get it to illuminate evenly. Whoever made that one did a good job. What I've done in the past (though not something that small) is get metal angle rolled into a ring (you'll need two) and build the frame around that. That way you have a nice strong frame. Melbourne is right on the ocean so I assume you have to deal with high winds at times. This sign lights nicely out to the perimeter so avoiding shadows is the hardest part. Even clear plastic will show a shadow. if you could get the customer to let you do a "channel letter" face with trim-cap that would make your life much easier. i suspect that they like that nice clean look and won't like the trimcap. The knife/fork are easily done on a CNC router and glued to the face. I really doubt that's lit with neon (though who knows). I'd use LED modules in a grid and add more to light the lettering. Hmm, I recently replaced LED's in a similar sign and I'll see if I still have the photos of the inside of the can. if so I'll post them.
if you don't usually make illuminated signs, you may be biting off more than you can swallow. I'm sure that there must be someone you could sub the job out to in such a large city.
