Upon doing a [http://www.ebay.com/sch/i.html?_odkw=%22Acer+Aspire+One+D255E%22+top+cover&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.X%22Acer+Aspire+One+D255E%22+cover.TRS0&_nkw=%22Acer+Aspire+One+D255E%22+cover&_sacat=0|search] on eBay using the terms '''"Acer Aspire One D255E" "cover"''', three parts came up. I believe the first is what you needed.
Acer also has a list of [http://www.acer.com/ac/en/CA/content/channel-partners|partners] that you may want to contact. I also found [http://www.cdsparts.com/|CDS Parts].