Hello Espanol David
Sounds like you got a real steal there - thats like A$3000 worth plus plus for A$680. Yikes.
If its all working well, you may not need to do anything for a while, other than make sure you use soft water (eg. Reverse Osmosis filtered if your local water is hard). That way, if there is any scale, it wont get any worse.
If you ignore maintenance for long enough, like, about 20 years, it may get to look like my machine (which is an earlier version of your machine) - check it out at http://coffeesnobs.com.au/YaBB.pl?num=1174998951 !
Im no expert, but it sounds like you dont need to worry much as its making good coffee. Maybe run some commercial descaler through it at some point, thats all. And make sure you use soft water.
All the best, si?