Complex sentence: There was, however, considerable delay in unloading the cargo; the whole administrative apparatus normally present was in Seville and Cádiz: inspectors, valuers, royal officials, etc., had to be awaited before anything could be put ashore.
Split into simpler sentences: There was, however, considerable delay in unloading the cargo. The whole administrative apparatus normally present at unloading (inspectors, valuers, royal officials, etc.), was in Seville and Cádiz, and had to be awaited before anything could be put ashore.