The oldest plat maps may be of some use, but the 1930 and 1944 only show farm plats...Sorry! I will try and post what I found tomorrow!
IF the Cornish stonemasons brought their skills from the 'old-world' (after spending some amount of time in St. Louis) and used them on quarried lime-stone here, did they have the same type of stone in St. Louis and/or Cornwall? If not how did they have to adapt to build either in St. Louis or in the lead mining reagon? Did they learn other tricks of the trade from others like the Germans or Italians?
I suppose interesting variations on the question are who did the quarrying, who did the stonework, and who did the designing/planning? Same or different people?Keep questioning the assumptions!