Leni â€” I would never suggest that a British collector or dealer invest in Bill Heacock's books as core reference works, unless you specialise in one or more British glass houses which exported extensively to the USA.
Apart from this, they are a generation out-of-date, and so should be read with considerable caution.
On the plus side, Heacock's works were always well researched from the US point of view.
The two I own were bought cheaply from a second-hand bookshop.
I suggest you borrow an example or two from your library before investing.
As for toothpicks, I don't really know, but I suspect that more items are labelled toothpicks in the USA than should be, because of Heacock's two books (there was a sequel). In Britain and Europe the opposite might hold true, i.e. some toothpicks might well not be recognised as such.
The situation here in the UK is complicated even more by the differing rates of Purchase Tax on tableware as opposed to flower vases and ornaments. So, rather like the multitude of vases sold as celeries, there may have been posy vases sold as toothpicks, mustards, salts, or spoon warmers!