If you wish to find out about the CH plate option for Victoria you can visit
http://www.aomc.asn.au/ and click on the Club Permit Scheme link which should tell you all about it. the AOMC are the body which the Victorian Mini Club Inc has to follow their rules.
You must be a member of a motoring club that is affiliated with the AOMC to be able to do this scheme. If you are a member of the VMCI you will be OK. You get a current road worthy and take it along with your car to the VMCI representative for the scheme (which I think is Noel Tippett) and he signs the form if your car is considered allowable under the scheme. Not much to it.
You could email
[email protected] and ask the club committee who is the person you need to speak to and their contact details.
Cost is about $80-90 that I remember. When you get the form signed you take it along to the rego board and they give you your new club plates.
Of course there are lots of restrictions that come with this scheme. You should find these on the AOMC page.
Good luck and hope to see you soon at a VMCI event.