that are delisted or no longer in existence. For example, DSL.NET INC, which has a CUSIP # 262506108. I tried few sources that matches stocks by cusip, but some of these old stocks don't show. I'm trying to clear few things with the IRS, so if you know how this can be done, please help me out.
If they were listed on major exchanges the Times and other publications have their papers on microfiche or other media.
Try contacting some of the historical data sites like tickdata.com. You should be able to find out quickly if they have what you need.
from google: Boston public library: http://www.bpl.org/research/kbb/stkprces.htm marketwatch: http://www.marketwatch.com/tools/quotes/historical.asp google "cusip # " with your number brings up some info including sec filings
it appears that you need to be a resident of Massachusetts for access to this database. Is there a way for non-residents to get a library card #? so far, I haven't had much luck finding what I need. I'd appreciate further assistance.