I don't dispute that. Certainly the tin trade was flourishing from very early times. I was making the point that this was probably a seasonal trade for Mediterranean vessels because of the dangers and difficulties. Lief Ericson reached America in about 1010 but there wasn't much trade between America and Europe for the next 500 years!
With regard to the tin trade, Cornish Tin was transported by ship to Britanny (Morlaix for example) and then by pack horse or cart across France to Marseilles.