The variations in spelling
people immigrating in the 16th, 17th and 18th centuries
were for the main part illiterate, schooling was minimal at best, and not all children from a family could be spared from farm work to attend school
now, depending on the brogue of the speaker, and the hearing of the clerk or whoever was the scribe, the outcome could be very variable, Bryce-brice-price-pryce, stuart-stewart-steuart-steward Buchanan-buchannan-bohanon-bohanun
and so it went on