what did the tax stamp imposed upon the American colonies as a result
of the Britis 1765 Stamp Act look like? Was it simply a doculment, or
was there some distinguishing stamp with some sort of image? For
example, if the tax was imposed on tea or paper or some other product,
was there an actual stamp that identified the item as taxable, or was
it simply a matter of identification by way of a list?

A Google image search, using 'Stamp Act 1765' (don't use the quotes in
the search window) will give you some good images and sources for
starting on what was taxed.

Best regards,

Omnivorous-GA