I’m trying to do something similar, but in my case I’m trying to add a custom action for USkeletalMesh. Doing it the way BobTellez suggested would require my tiny little IAssetActions-derived class to implement all the functions that FAssetTypeActions_SkeletalMesh overrides, finding the correct FAssetTypeActions_SkeletalMesh instance inside them and calling its implementation. This would be extremely brittle.
Is there a better way for me to simply add a single menu item that runs a tool on the selected USkeletalMesh asset in the content browser?