I reached out to Patrick Blatter (Robert Blatter is his uncle) and he asked his uncle to confirm what his Dad had told him. These pipes date to roughly the mid to late sixties. The stampings are part of a pricing system that existed at the time. This is before they started to mark their pipes “2 89” (for example, 2nd pipe made in 1989).
This pre-dates when they started properly stamping their pipes:
S = 10$
7 = 5$
So your pipe was made back in the good ol’ days, and it was $30.00 then. That would be roughly $290.00 in today’s dollars.
That seller is really terrific. I bought my most recent Blatter pipe from her and I love it. Great little find for you, Sir!
Eric