Pseudonyms should stay. You can find the proper way to handle them in the Librarian Manual:
"Regarding author pseudonyms or pen names - some authors write or have written under multiple names. When editing or adding information for a book written by an author with multiple names, enter the author's name as on the front cover as the primary author. The author's other names may be added in the other author fields. Original name or other pen names can added and linked via a Librarian Note: in the description field, or using the Librarian Note feature located above the Title field. In some cases, a book may be originally published under a pen name, but then later reissued under the author's original name. When this happens, the author listed for any and all editions should be the author name the book was originally published under - so the reissued edition would need its primary author name changed to the originally published pen name, with the additional name added as secondary for all editions with it on the cover. Doing this will allow the various editions to be combined.
Authors with books published in multiple languages should have their names dealt with similarly to those with pen names. All editions should have the primary author name as the standard or most common Roman (that is, English-language) version of the author's name. Editions published under another spelling of the name or the name in another language should have that name listed as the secondary author.
Different editions of a book not having the same primary author can cause quite a few distinct problems. Please keep the primary author for all editions of a work the same."
"Regarding author pseudonyms or pen names - some authors write or have written under multiple names. When editing or adding information for a book written by an author with multiple names, enter the author's name as on the front cover as the primary author. The author's other names may be added in the other author fields. Original name or other pen names can added and linked via a Librarian Note: in the description field, or using the Librarian Note feature located above the Title field. In some cases, a book may be originally published under a pen name, but then later reissued under the author's original name. When this happens, the author listed for any and all editions should be the author name the book was originally published under - so the reissued edition would need its primary author name changed to the originally published pen name, with the additional name added as secondary for all editions with it on the cover. Doing this will allow the various editions to be combined.
Authors with books published in multiple languages should have their names dealt with similarly to those with pen names. All editions should have the primary author name as the standard or most common Roman (that is, English-language) version of the author's name. Editions published under another spelling of the name or the name in another language should have that name listed as the secondary author.
Different editions of a book not having the same primary author can cause quite a few distinct problems. Please keep the primary author for all editions of a work the same."
Also see this thread.