BVK is the 2nd run of VKs - first was AVK.....
this usually changes over when the ADR list on the plate is updated.
Then it's simply a sequential number out of the plant, and the A on the end is Elizabeth (Adelaide) South Oz.
Hope that helps mate.
I asked questions about my car, wrote all the info from the engine plates down, and got alot of information, all the prefixes are explained [thanks to maxim]. The thread is located:
How to find detailed information specific to my VK Berlina?
You might get anything else you need
Kurt