To my knowledge, there weren't E420
Limited Special Editions available in Europe, AFAIK only in the USA and Canada (but without any SA Code)
From
this link:
"The Special Edition models were introduced around April of 1995, so not all 1995 W124 models were Special Editions. The Special Edition package included special metallic paint, special 6 hole alloy wheels, integrated analog cell phone, trunk mounted six-disk CD player, high performance 10 speaker sound system, drivers seat memory, electrically adjustable steering column (no tilt), stainless steel door sills and burl walnut interior trim. On the E320 and E300 diesel the extra cost was $1,295 for the options that were worth about $4,300. The E420 package cost only $495 since it already had burl walnut trim, driver seat memory and the high performance 10 speaker sound system. Paint colors available were Moonstone Grey, Azure Blue, Sapphire Black (exclusive to the Special Edition) and a new color called Brilliant Emerald Green. I think these were the only colors used on the Special Editions.
The official Mercedes Benz of North America position was that the release of the 1995 E Class Special Edition was to celebrate the 10th year of production of the W124 series. I think it was more likely that back in 1995, Mercedes had a tough time moving the W124 E Class since the new W210 E Class was going to be released in the 1996 model year. Lexus had also been taking sales away from Mercedes Benz. I’m sure the real reason for creating the Special Edition model for the 300D, E320 and E420 was to spur sales."