This pipe was carved during the "factory period" (before 1964) but it was marked with a green dot which only appeared in 1964 and was continued untill 1967. After 1968 Blatter pipes were marked with the red dot. The stamping corresponds to a period ranging from mid 70ies to 1981.
More about Blatter markings...

Blatter & Blatter Inc.
Pipemakers since 1907
Artisan: Robert Blatter

The spot may be discolored

Artisan: Peter Brakner †

 

Brand created by Alberto Paronelli in the 1970's. Pipes usualy were crafted by Tom Spanu.

Blue dot

 

Artisan: Gregory S. Clemons

Inderwick & Co was founded in the early 19th century by John Inderwick. The warehouse was situated 58 Princes St, Leicester Sqr, London

 

▲ This is a pre-WWII churchwarden pipe.

House brand of the amsterdamer tobacconist. The rear area of the shop makes a place for a tobacco museum and library, along with a lounge where customers can order drinks and relax with their favorite smoke.
Address: Rokin 92-96  1012 KZ Amsterdam

 

 

In the context of the Sasieni/Dunhill trial and according to Stephan Smith:
"In an initial attempt to comply with US patent law, Sasieni moved the one blue dot to the side of the pipe.  This unfortunately didn't do the trick, and only a few side dot Sasieni's were ever made, which are now extremely rare and collectible."

 

Blue dot on top and "S" on side of stem. A stem marking with a unique blue "S" exists too.
Probably dating from the late 1970s like "Claret" serie.
Other Sasieni transition pipes here

 

See also Carlyle as a brand.

Older logo

▲ Each member of Wally Frank's "The Pipe of the Month Club" received a brand new pipe in the mail once a month.

 

Brand from the Bradberry Pipe Corp. NY
(J.M. Lopes, op. cit. p 247)