G. Boley C60 watchmakers vise date of production

[Chase]

Hi, 

I have a vintage/antique G. Boley C60 vise that I'm refurbishing. The G. Boley C60 as with other tools they made where/was/is primarily used by watchmakers and I'm hoping the watchmaking/repair community can help me with a question. 

Did G. Boley put a manufacture date on their vises? 

The number "157" is stamped on both the static jaw and dynamic jaw on my particular vise. 

Is that the date code? Or number vise produced?

Anyone know for sure how to date these vises?

Thanks

[Chase]

My apologies Admin, I posted this in the wrong section. I've reposted the question in the correct area so you can delete this post.

Thanks.