Thanks to Uwe H. for this link to a Baur for sale in South Africa.
"E21 323i Baur Stuttgart no: 13 collectors item, cabrio, Burgundy, bucket seats, engine redone a month ago, new centre baring. jvc frontloader, 17" flawless rim. R58000 neg."
It is interesting to note that this is listed as a 1984 BMW 323i. However, it is clearly an E21! Uwe did some checking and here is the VIN: 7252879.
As you can see, the production date is December 1980 (and it is right hand drive), so it is clearly an E21. Apparently this Baur sat for a long time before being sold. We are also seeking information on when the Baur conversion was done. This too could cause a delay in getting the car to market. Plus, it is a right hand drive, and that limits its marketability to the UK, South Africa, etc.
It looks like it was registered in 1984 for the first time. Hence it is listed as a 1984 model. This is not the way we do it here in the US, but apparently this is how it is done in South Africa.
The Baur number is 2500, which is also consistent with a production date of December 1980.
Here is the link to the ad: