Dating a Comoy's Grand Slam

Once I get to a decent keyboard I'll answer this for you.
Rob

The first is dated from the early post war era to about the late seventies. The patent wasn't stamped after it expired and the numerical stamps used for Comoy's changed from the distinctive numerals seen in your first example to numbers more akin to those used by GBD for example. I am not sure if this change occurred with the change of ownership (I suspect it did).
The second pipe is most likely a very early post-war pipe. The difference in patent numbers was not era based, instead Comoy's used the appropriate stamp for the recipient market (2001612 was the US patent). The second pipe was intended to be sold in the UK. The time overlap between that particular COM and the patent stamping was apparently quite short.

To further add, the US patent for the 'Grand Slam' apparatus was approved in 1935 and expired in June of 1953. US market pipes after that would not have born the patent stamp. The UK patent was roughly contemporary.
It is not known with ANY certainty when the Made in London England stamp started, but it is commonly accepted to have begun being used in the 1945-1950 time frame.

What is the shape of the second pipe? I have an idea....

I have two GS pipes. I did a little research prior to buying the first. Here's what I learned from various sources.

Comoys had 3 separate patent numbers for the Grand Slam pipe series. Canada 3441422 granted in 1933. British 405743 granted probably in 1933 also. USA 2001612 apparently applied for in 1933 but granted in 1935.The comoys stamping prewar and wartime was straight line, all same sized letters without apostrophe with the smaller patent stamp below.The earlier pipes were also marked London Made in a football shape.The stems were inlet-ted with the white/blue/white bar. The patent number was marked British rather than UK. At the end of the war 1945 or so, the bar was dropped in favor of the 3-piece C.The patent designation was changed to UK pat 405743 and the circular Made in London England was started. The word Patent apparently was continued until the patent ran out in 1953 ?? It was replaced by the word Pipe after that and the patent numbers were no longer used. The stingers were also made slightly different after the war.That's all I understand about the subject and I'm certainly no expert so the above is open to any correction, please.Thanks for looking ! Hoppes

Here's an early prewar or war time Grand Slam:













Here's a post war pre 1953 Grand Slam:







Here's both--prewar on top:

Can you find prewar and war-time Grand Slam pipes without the white/blue/white bar or the 3 piece C on the stem?

I’m glad to have found this thread. I’ve five Comoy estate pipes, two of which have the small ‘white/blue/white’ strip. When I get the time, I may post pics here to get second opinions about the years of production. I’m keeping all of my pipes, so the interest is purely to imagine the history of said pipes. They’re all fantastic little smokers, btw.

I would think a Grand Slam should have either the early white-blue-white bar or the later 3 piece C. Anything else probably would be replacement. Hoppes

I just recently acquired a Comoy's Grand Slam. It has the inlaid bar on top of the stem. On one side of the shank it has in three straight lines, COMOY'S, GRAND SLAM, PATENT. On the other side it has MADE IN ENGLAND in a circle. To the right of that it has U.S. PAT. and then 200612 underneath. To the right of that it has the number 22 which I guess is the shape number?. On the bottom of the shank it has *2 which I believe somewhere else someone mentioned this refers to the size of the gasket on the stinger?
Does all of the above date this pipe to the 30s? It's in great shape