Dating metal tacks

Does anyone have information on the historical manufacturing
processes used in Europe and North America for making metal brads
and edge-tacks since the 17th century?  Samples are commonly found
on furniture upholstery and along the edges of paintings. There are
some published sources which discuss nail technology, but I've seen
nothing that specifically deals with small tacks and brads.

Aside from assembling a reference collection of dated samples , I'd
like to find a reference which illustrates what elements we should
look for to ascribe a date to these (often) rusty old things.  In
this way we can be better positioned to propose a date for an
undated object or for a previous restoration.

Michael O'Malley
Centre de Conservation du Quebec

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                  Conservation DistList Instance 13:20
               Distributed: Thursday, September 16, 1999
                       Message Id: cdl-13-20-023
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