How do I merge your Gravity data with Comtrade or WITS trade data?

In most cases, the iso3_o and iso3_d codes should match without issue to bilateral trade data. The combination of iso3_o, iso3_d, and year uniquely identify an observation in the dataset. However, the table below describes several countries that we are aware of with different letter codes in the Dynamic Gravity, Comtrade, and WITS datasets.