Agreed, these are indeed E55 wheels, but they are also R129 optional wheels, in fact the part numbers on these wheels are split between 210's and 129's. From memory, I think the front wheels have a 129 P/N, and the rears are 210 P/N.
Also in answer to Injam's question in the first post about the best fitting et for the fronts, 40mm is not a good fit for E500E , maybe for a NON-E500E, but E500E's share the same wheel sizes as the 129 SL's, with ET's in the mid 30's and lower. Numerically lower ET's move the wheel/tire towards the outside fender, numerically higher ET's move the wheel/tire towards the suspension. The wider fenders and wheels wells of a E500E were designed to give the E500E's a wider stance, moving the wheels towards the outside of the fender. That's why stock 16" E500E wheels are 8" wide and have an ET of 34mm. You will not typically see any front wheel meant to fit a E500E with an ET numerically higher that 34.
These are great looking wheels, you won't go wrong buying them, and if you want another look some day, they will be relatively easy to sell again.
good luck...