What is the meaning of the R&S ?
Maybe these folks can help:
Sears & Roebuck?
No help,old site.
I really think you got it right Robert.. they so sell tools and have a long time.
While that might be the answer, Sears would have had to pay Ford to use the Ford script on the pliers. Why would Sears pay Ford, they would want their (Sears) name on them to remind customers of where they got these swell pliers. Sears being as big as it was, would not have gone on unnoticed if it was using the Ford script. There was a company named Ford but they used their own typeface/script on their tools. (Sears bought Craftsman around 1926 ish)
Service & Repair!
They are Model A Oct 1927 to Jan 1928. Part of the tool kit supplied by Ford. They could have been used late in the Model T production also. I could not find who S&R was.
Siegfried & Roy
Sears and Roebuck could be S&R who owned Craftsman..
Just my 0.02cents
This article seems to rule out Sears and Roebuck.
It's an interesting site with lots of info on old tools.
...and a table with manufacturer codes of Sears tools is near the bottom of this page. http://alloy-artifacts.org/craftsman-early-tools.html#mfg-codes
Sadly no S&R.