I found a 1k CD in my son's and my name (as custodian) that dates back to his birth in 1988. It is the original certificate so appears to have never been cashed in.
How do I find out and redeem it (hopefully? The bank is no longer in existence in CT - it was Gateway Bank who was bought up or merged. Any ideas?

Thank you

You might check with the department of bank for Connecticut. Though after that long a time I suspect the odds of recovering the money is slim.

Department of Banking
260 Constitution Plaza
Hartford CT 06103-1800
860-240-8299

You might also try checking for "unclaimed money" for CT. I'd be careful searching that online cause it sounds like a good subject for a scam. Maybe try the state treasurer's office.

Many times unclaimed assets are advertised in the paper and if unclaimed revert to the state, not the bank.

This site might help you :

DOB: Failed Banking Institutions in Connecticut

Also, here is the site for searching the State of CT's "lost asset" list. By law, any financial institution that can't locate the owner of assets under their control must turn those assets over to the state. The states in turn all run web sites that allow you to search for those assets and reclaim them. For CT, see:
Office of Connecticut State Treasurer Denise L. Nappier