Harold -- This might work for you. There is a Dutch word *bouwmeester*, that means 'architect' and/ or 'surveyor' (see Sewall's Dutch-English Dictionary, various editions between c1700-1750). In this same dictionary, *bouw* is given for 'building' -- and of course *meester* is 'master'. I do not know what this would be in German -- but the languages were close. If this is the meaning of BM, it suggests that the men who had this after their names were the designers / architects of the building. Perhaps that was their only role (though they may had a hand in or directed the construction, etc.), while the other names were the names of the men who built it. Ruth Piwonka Kinderhook