Mk 1 firing rest variations

[BCA]

Just for the record I have noticed the following variations the 16" division plate RH firing rests. The earliest (?) is a full 16" long and 1-5/16" tall while all the rest are only 15-1/2" long and 7/8" tall. All are 2" wide. It appears that the transition from rubber to wood occurred sometime in 1942.
Rubber versions:
No part number: 1-5/16" tall x 16" x 2" (earliest version? taller and longer than later)
TL 13003, FM Co 41: 7/8" tall x 15-1/2" x 2" wide.
CTL 13003 B: referred to in FUC-03 but I have not seen one marked with "B" suffix.
CTL 13003 C, FM Co 41: "C" is just an ink stamp, not punched
CTL 13002 C, FM Co 42, DR Co 42: "C" is punched along with rest of part number.

Wood version
CTL 13003 D, FM Co 1942.

Has anyone seen a "B" version?
Brian

[Lynn Eades]

I have (rightly or wrongly) identified the British carrier ones from the Canadian ones, by the extra height.

[BCA]

Lynn, Thanks for the comment. I have looked carefully for parts numbers on the taller/longer firing rest and there are none, so it may be British. Ford Canadian carrier parts are so well-marked with part numbers.
I have often wondered why Canadian Ford carriers didn't follow the standard Ford part part number scheme (for instance all carburators had the same part number but the variations were specified with the alpha-numeric prefixes) but now realize that Ford was probably complied to use the existing British carrier part numbers.
....... Brian