Some references to Danco pipes from the book "Who Made That Pipe?" and they put the manufacture of them in both Denmark and the US but do not attribute it to any specific maker. The ads on right indicate the location of the firm was on Hudson St., in New York.
Some Danco pipes are marked "Imported Briar" and that would suggest they are American made.
Some Danco pipes that are marked "Italy" so the US Danco distributor/seller must have had some of the briar pipes they sold made in Italy.
Danish Dancos should be stamped "Denmark."