I live 30 mins south of Canberra, I will try to get some pics over the weekend and pm them to you.
The tank has no tap or cap but is in fairly decent shape for it's age, it is yellow and has a couple of very small dents and will need painting.
The seat is complete but will need a cover, I believe it is from a YZ125C as well, but when I get some pics I will take some measurements of the mounting points so that you can determine if it will fit or not.
I haven't really thought about a price, it's been hanging in my garage for about 12 years gathering dust alongside a coffin tank from a Maico.
I'll work out a price for the tank and seat separately in case the seat won't work for you, or if you have a price in mind once you've seen the pics, just let me know.
Tony.