Let's try not to make things more complicated than they already are.
As some of you have pointed out, we already have a boiler plate 670 for citing the results of an OCLC search. Presumably, one found the Swedish bib record and its headings in OCLC and it would be correct to give the information in a separate 670.
Attaching the information to the 670 for the item in hand is a bit misleading, and can lead to confusion.
Anthony R.D. Franks
Team Leader, Cooperative Cataloging Team
Library of Congress