I sent Steve a Spooks EM rifle backglass for him to restore and it took 3-4 months total. Awesome product and he estimated that time frame right from the beginning.
No, it's not the same process the original manufacturers used but it looks damn good imho.
Here are more pictures of the game with before and after BGResto pics...
https://photos.app.goo.gl/XBomYrE0vjg6yQah1