For sport models (97-98) which came with AMG monoblock II, the offset is 35/31mm front/rear, respectively. For sport models (99-02) which came with 5-spoke AMG, the offset is as Bob said, 25/23mm front/rear.
I have no idea why it was like that. I've had both sets on my cars and they both working fine. At first, I'd thought the 25/23mm offset was a bit "sticking out" but when I had 285/35ZR18 tires on my rear wheels, I had to use 3mm spacers.
If the (23mm + 5mm) 28mm offset needs spacers, why wouldn't the 31mm? [V][?]
Do different kind of rims require different offset numbers?