Thanks to Ming we can be certain that it has come from Hong Kong or Taiwan.
I would have to disagree here, while there is the possibility it's from Hong Kong or Taiwan, there is no reason why it shouldn't have been produced on mainland China. Simplified characters were first introduced in 1958, the reform of the writing system being completed by 1962, so if the vase was produced in mainland China before this period it would feature non-simplified Hanzi.
Likewise China produces a large number of reproductions of historical items, both legitimate items and outright fakes. These typically feature non-simplified characters. Indeed most mainland Chinese can read non-simplified forms, even if they can't remember all the strokes to write them correctly and only a relative few of the thousands of Hanzi were ever simplified.
Regarding Heinrich Wang, the works by him which I have seen have been 'Liu-Li' type pate-de-verre/ pate-de crystal items, rather than blown vessels such as this. There are many many glass producers in China producing very fine pieces, similar in style and quality to Wang's work, but sadly western companies seem completely uninterested in importing any but the cheapest pieces of oriental glass.
In my view, this vase does look more typically Mainland chinese. Closer photographs of the engraving and lettering may give clues to the date.
Steven