Unclaimed property 1099s usually are issued by the states. You can check with your state to get more information or just enter it as an 1099-INT since the dollar amount is marked as taxable interest. You should be safe with that entry.
Only 1099-B has a Box 5 that can be checked for "non-covered securities". But it doesn't make sense to enter it as 1099-B if the only amount on the 1099 is taxable interest.
