There is reference to a similar pair here: https://stargazerslo...ts-the-minimum/ - These were apparently labelled "Viking by Panorama", but these are very similar and labelled "Viper by Panorama"
- according to these references they might have been made by the Tohyoh Company, based near Tokyo... As you pointed out, the oval-shaped sticker label seems to be a faded version of the standard QC label that was placed on Japanese optics.
All the best,
(PS: Just edited this: the second link wasn't working: and here is another link to Tohyoh 20x80's: https://www.worthpoi...-wide-170054436 )
Edited by DeanD, 11 July 2020 - 07:48 AM.