Thanks for posting.
Your candlesticks are definitely late 20th century. They could be the work of Liberty Village, a short-lived open air museum of sorts like Sturbridge Village which had craftspeople making historical wares.
As for Caspar Wistar and his glassworks, why not start with the Wikipedia page - https://en.wikipedia.org/wiki/Wistarburg_Glass_Works
As for value, replica glass like this gets at least some interest. I see Liberty Village pieces sell in the $25-50-75 range...more for better forms but it is a super specialty market.
Hope this is helpful.
