Phil - Sorry I do not know what the extra letters designate.... Your "R" above the serial number is just one example of extra letters. There are letters after the numbers, and below the numbers on various Bear Bows.

We may have to do an actual study of these extra letters, something like the study we just got started on about the 1959 Kodiak Specials on another thread.

Give me another day or two to try to get others to help with a first draft of the next group of Grizzly bows to date...

Brad - Your Second bow #25912 red glass is really a single shelf 1953 with a second shelf added or wedged inside the leather grip. I've seen this on several bows including Bear Grumleys.

The true dual shelf has both shelves cut into the riser wood, not added inside the leather grip like yours... Thanks for posting the photographs

Just modified the dating system to reflect these changes... check it out now... there may be a clearer way to word the text...

Here are some pics to go along with Wade's descriptions:
The Grizzlies from 1949 to 1954 in order top to bottom:

And the side view, 1949-1954 left to right:

And  the full view

More to follow

Wade, yes I see it now, good distinction to note.
Also looks like the riser shape was made more angular in Bjorns '54

Great info and great looking bows.

Thanks to all that contributed to this thread.  

Dating early Grizzlies will be much easier after this.

Awesome guys    

Trap