Kinda funny how marbles seem to migrate together. Looks vintage to me based on the similar ones I've come across, and vintage Alley would have been my first guess.
As a side note - A family member recently brought me some childhood marbles and I mentioned the 'modern' word. Modern for a lot of people, doesn't mean 40-60 years ago, is how the conversation went, and we joked about getting older. I enjoyed that visit. Good times and some marbles.