Figured this would be the appropriate time to cover what little is out there in manga form for Walkure Romanze, which of course is based off the fantastic Ricotta created eroge by the same name.
Apparently there are two ecchi manga spinoffs for this series. The one you see here publishes with nudity in Comic Valkyrie magazine. Deux Ex Scans currently has it up to chapter 8.
As far as the fanservice, like the anime the nipple sightings are brief and (relative to other ecchi manga) uncommon; this manga series compensates by putting a relatively heavy emphasis on pantsu and butt shots.
Walkure Romanze (8 chapters, ongoing)
I also randomly stumbled across some figurine photos for Celia that someone was nice enough to snap and upload, figured I’d share those as well (these pics are very high resolution, which you can see by downloading the file below or by viewing the image in the gallery and clicking ‘copy image location’ and pasting it into your URL).
(Download link contains both galleries)
A different ecchi spinoff for this series was published in Monthly Comic Dengeki Daioh and ran 14 chapters. The magazine version is non-nude but appears to be censoring nipples, meaning the tank version could be great, if anyone ever scans it. The censored chapter versions of it can be found at Jcafe.