I love the idea of there being more (and more varied) pre-Columbian incursions into the New World, but the evidence provided here just doesn't make any sense to me. Swords and spears made of lead? Several large, lead crosses made by a Jewish community? Yes, caliche is tough and can take a long time to form, but it can also be more or less laid down like cement if you have enough water.
Signs point to these artifacts being a modern creation, and without some sort, any sort, of other, corroborative evidence, that's what I have to assume is the truth.