Vintage Firecracker Question

[displayfireworks1]

These photos made it to me from someone on the internet that is curious about what it is they have. The question he has is from what time period are these from. I am not sure what he wants to do with them. I do have his name . email and phone number. Here are the pictures if someone can comment.
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http://pyrotalk.com/wp-photos/wp-content/gallery/united-states-pennsylvania/0fw3-5bb41fb3a56745fc06d2783b20af8565529b0abf.jpg
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http://pyrotalk.com/wp-photos/wp-content/gallery/united-states-pennsylvania/0fw4-85356f1b090d90382b1774d50acf24c802dcb1c8.jpg
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http://pyrotalk.com/wp-photos/wp-content/gallery/united-states-pennsylvania/0fw2-1f372ff6767586723ceb111dac193875c35ded2d.jpg
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http://pyrotalk.com/wp-photos/wp-content/gallery/united-states-pennsylvania/0fw1-15200ca78026fdbf47e2683b7420be325180971a.jpg

[displayfireworks1]

If anyone is curious , I got an opinion on these from a firecracker collector. While these are old, they are common. Word is they are from San Francisco China Town. Value $75.00 to $100.00. i told the person that made the inquiry. My guess is it will take him six months to realize the reality of it. Just because something is old does not necessarily mean it is valuable.
I can't wait to see what is for sale at the PGI convention this year. I may buy a few things.