Interesting car. This CSL is not previously well-known in the "CSL-community". I'm pretty sure it's a real CSL. Because of three important facts:
1: The VIN is correct for a Ceylon CSL (it's in the midle of the batch of some Ceylon CSL-cars)
2: It looks like the car has black headliner + black sun visors
3: With almost 70% (of all produced RHD CSLs) currently traced, it wld be very difficult for someone to "invent" a CSL with the correct VIN and within the correct color-batch. There are not many unknown RHD CSL VINs "available".
I agree, the car looks "suspecious" without the wheel arch trims and the presence of standard style E9 seats + headrests. But there cld be explanations. City pack CSLs, and specially the RHD CSLs, cld be ordered with standard E9 seats. Not officially, but still possible at the time. The wheel arch trims, cld have been removed. The additional side markers were mandatory for US-import at the time.
However, in order to be sure, the engine bay must be controlled and, as always, the engine nr (2285345?) is a very valuable hint.
I wld say, it looks like it's the real thing.
Cheers
Henric