Steve
Even though one can see a catalogue machine - you will always sell better if you have an actual photo - and in your case the machine is in 1st class nick so the photo will show this.
Posting a photo is easy - the hard part is remembering where it is on your hard drive.
When you are writing a post go to the bottom of the box and you will see "Additional Options" - click on it.
Go to Attach: and press "choose file"
You now go to your photo on your machine and post it
Its really that simple.
You may encounter a problem if the photo is digitally too large. But you can reduce. If you have to do this come back on for further info.
Joe