TubeNet

Nearly all works of Shostakovich are under copyright in the United States till roughly 2045 (Shosty 13 would fall under the old copyright law of 95 years from publication date since it was written prior to 1978 so it won't be public domain until 2057.) You might be able to see if someone still has a copy of the Torchinsky Excerpt books that include his stuff, but I think you're out of luck for getting the part early (excluding renting it for yourself which may be more difficult than obtaining the Torchinsky book).

This contains a list of 171 libraries that have a full score to Shostakovich 13:

http://firstsearch.oclc.org.ezproxy.ita ... agenum=4:0

You can visit your local library and, unless it's one of the 171 on the list, request an Interlibrary Loan.