The part number for the 300sl Gullwing, a W198, is 40 198 880 00 23.

The part number for the 190sl, a W121, is 40 121 880 00 23.

The top bar, the round Mercedes logo in the middle of the grille and the chrome
wings' to either side of the logo look the same but the bottom bar is different. There were three different bottom bars for the W198, only one for the W121.

And they all appear to be different.

Search the part numbers above and perhaps you will find examples. The difference is sometimes slight but would still be apparent once the grille was on the car.