Tele Vue have produced some NV accessories and also sell NV gear but not OS due to restrictions. It is a pity that restrictions are in place but I can understand why for not everyone wants to use it for astronomy.
See
https://www.televue.com/engine/TV3b_page.asp?id=36
(Some links at the bottom of the page may be useful).
In fact I think that if you are in the US and at a star party with NV gear on show, you are not allowed to look through not being a US citizen. I cannot remember where I read that and could be mistaken.