There are a FEW certificates that do indeed retain some value as securities. Those may include stocks and bonds from companies still traded on world stock exchanges.

They may also include uncancelled certificates that have been absorbed into existing companies. And there are certainly instances of uncanclled bonds maintaining some of their face value even thought the companies have been declared insolvent.

Roland Smythe (the namesake for the current RM Smythe & Co) made a significant income trading in just those kinds of securities back around the turn of the century .

However, it takes a LOT of knowledge. Far, far more than what I possess.

The main thing to understand is that just because a certificate is uncancelled does NOT mean it is worth any more than its collectible value. And, because research is sometimes very tough, it will cost you money to have someone research your certificate.

As a rule, I will suggest that if many such certificates are being bought and sold among collectors, there is almost no chance of its having security value.

Again, estimating current security value is substantially beyond my knowledge. Please click on Value as Securities to learn more about the issues surrounding such valuations. You will also find links to specialists in the field.