Before starting to answer this question you need to be aware of the various Mokes made and where they were made as this can have some bearing on what is available and what is going to suit your vehicle.
English Mokes and Australian Little wheelers(1966-1968) share pretty much all the same panels. From April 1968 onward the Aussie built Mokes still share a lot of common panels but they also produced some special panels to handle the bigger carby and the bigger 13" wheels and Export mokes
In 1980-82 Australian Mokes came out in 'Galvanised' shells and again some more unique Moke panels were produced around the different fuel tank and other minor changes. Production moved to Portugal where they started out using the remaining Australian stock of panels and more or less produced the Australia Moke. Cagiva then relaunched the Moke with their own changes with panels reverting to the early English panels. As the same presses and dies appeared to move from each country many of the panels are dimensionally the same but you do need to confirm the panel you may be purchasing fits your particular model of Moke.
In the past 10 years the Moke brand has come out of China/Queensland with with full body replicas being produced which looks pretty much like the original Moke, however the production and manufacturing process is quite different so very little if any would be considered a direct replacement. More like you will get something that resembles the original panel and then it will have to be cut/welded to fit your application.
Two English companies are between them are producing many of the panels required for rebuild a Moke, including complete body shells(which are probably not legal to register in Australia so do your homework well if this appeals to you), and they are supplying some of the Australian parts suppliers. For people in Australia the shipping costs tend to kill the idea of bringing in a floor pan, sidebox panel or any of the other larger most requested items, but that may have changed.
A UK based company who purchased from Cagiva the remaining stock and the equipment to manufacture the original Moke body and panels.As far as I am aware they do not have anyone in Australia distributing their goods.
Another UK business reproducing many of the panels for Moke from their own tooling and have quite a range at the time of writing. Best to check out their website
As far as I understand Minisport are the local distributor for Moke Panel products
Located in Sydney, John has a fair amount of new old stock when it comes to Moke panels so perhaps he can help you out if you give him a call or email. I don't believe he has floor panels however most of his stuff came from the Australian factory when it closed up.
Moke Australia don't appear to be trading to the public anymore. Dec 2017
This is the Australian arm of the China Moke which do offer panels but as stated earlier they may be of similar dimensions but in most cases are a different construction so not always a simple direct replacement. If you do your home work and are handy with a welder then perhaps some panels are suitable for the restoration of an Original Moke.
This book provides details of panel fabrication and repair for the English Moke which can be of some benefit to the Australian Moke restorer so best to have something to confirm Roy's measurements suit your Moke but still a good reference for the home restoration.
Depending on your location, getting into the online Australian Moke Forums and asking if someone has suitable panels or samples is the next best lead. Sometimes people may have a body that is too far gone for restoration or to send to England, but the panel you are after may still be salvageable or they have bought in panels that they decided not to use.
The Australian Moke Forum - Australia
UK Moke Club Forum - England