Hmmm. I could be wrong and I don't mean to cause alarm but it kind of looks like a keg set up for cleaning beer lines etc, but I'm not sure. You make have to buy ball lock posts to fit into the keg (removing the ones on it), as it looks like a Rheem or Mytton keg your going to have to try kegsystems.com.au, estimated at around $20 each for the posts as these kegs are pretty old and parts are scarce. Guess you'll just have to wait until it arrives and see what you've got.
Good luck though, I hope it turns out. Just for future reference too I think kegsystems still sells 18L kegs for about $70 each and he's in NSW. Either that or an order from brewersdiscount for about $50 each delivered.
Hi Manaen there are a few more kegs for sale here that look the same as yours, I'd hazard a guess that the connections are just old style not like the ball locks that seem to be around a lot now you might just need a different fitting to fit in it. Good luck.
I downloaded the image and zoomed in on it.
While the piccy isn't all that clear, it looks like it could be ball lock fittings with another fitting on the gas and beer posts.
Hopefully those should just pop off and a clean up, seal kit change and you'll be in business.
Post better pics when you receive it.