These conversions aren't cheap, and some of them look better than others. Like everone has said it's certainly not the same as the next model up, but if you like it, go for it. I have seen ads for companies in California that do these conversions in the DuPont Registry. You should be able to find a copy at a decent magazine stand or bookstore.
1995 E420 - retired
1986 420SEL - retired