I am not familiar with Chapman, but have some information that might help some get equipment from this period if they dig for it.
Francis Bannerman and Sons became a surplus buyer and retailer at the close of the U.S. Civil War on moneys made from marine salvage operations. For over a hundred years the company supplied surplus in varieing lot sizes worldwide. It is my belief that material may still be languishing in warehouses or stuffed away in storage areas.
Check older warehouse sites.