To my knowledge those flywheel screens 604272 were never chrome from the factory. The retaining ring around the perimeter is aluminum and sometimes polished, and the flywheel nut and the washer underneath is either chromed or polished aluminum. Those screens (p/n# 604272) were used in the 60's and were just painted various colors depending on the year of the machine, mostly blue, but sometimes green in the later 60s. Around 1968 or 69 they did come out with a chrome screen for the D-400s, but the part number was 605298. My guess is that you are wanting the later version with part number 605298? Below is a pic of the 2 different screens, the 1966 has the 604272, blue painted screen, the other one is a 1973 7260B with the chrome version part number 605298, the chrome version sometimes had a different color center plastic cap depending on year and model. Hope this helps.