Can't help you with that but I'm loving the Joey Karate pic.
There is a massive data dump of sig serial numbers on a different forum. I'm surprised google didn't get you there.
I was able to get mine to a couple months based on others entries. You can apparently call sig And they will tell you for a fee.
i found G157### and G159###, not G 158###
I had similar, but had to infer less because of more people with serials close to my 226.
Least you get an idea




























