I have tried to explain this in other threads, but here goes again.
If you look at the photo of the 190sl top and moulding you will see that the sewn seam along the rear bow does not extend across the ceneter section of the top, this seam was left unfinished when sewn, then the top installer would fold the material under, tack it to the wooden frame then the chrome strip was installed to cover up the tacks.
the blue top on the 230sl has the seam sewn all the way across the top and appears to have been made in the same manner as the 65 and later tops with the metal rear bow.
The later top can be made to fit on the wood bow frame, but the chrome strip no longer serves any function, it would be just ornamental.
It would be interesting to see whom if any one still make a correct early 230 top cover with the unfinished rear seam (as illustrated in the 190sl photo) or do they all just sell a 250/280 top as a "fits all".