[TR] Narrowing in on a lost commission number

[nwolf at u.washington.edu]

Hi everybody
   Here's an unusual request:  Would a few of you early TR4 owners mind going out to your car and checking the diameter of a certain hole?  Here's why:

   My TR4 has a sordid past.  At some point, it was separated from its original commissioning and body ID plates.  It currently has '4A IRS plates (and title), but it's obviously a TR4.
   I've been trying to narrow in on the body tub's original commission number using the production body change points in Piggot's "Original Triumph TR4/4A/5/6" and in the Moss Motors catalog.
   So far, I know for sure it's a '62 or a '63, because it has vertical door check straps (up to 22342CT) along with a 3-piece rear deck panel & automatic boot lid stay (from CT5643 onward).
   The only other relevant change point I could find involves the hole for the fuel tank vent, which (according to Moss) changed from 1/2" to 1" diameter at CT11664.  If this is valid, it would narrow the range down to CT5643-CT11663, or mid-1962 (my car has a 1/2" hole).
   Can anyone confirm that this is a real change point?  I would be eternally grateful if some folks on either side of CT11664 could report on the hole diameter.  The hole in question is in the right side of the boot, hidden behind the gas tank casing board, but accessible by touch (without removing the board) if you're flexible and you know where it is.  Here's a photo of mine with casing board removed:

http://tinyurl.com/36vnau

   Note that your car may have a pipe and grommet going through this hole... but I imagine you can probably still distinguish between a 1/2" or 1" hole even with the grommet in place.
   Thanks very much in advance!!  I will compile and report the results.

-Nick Wolf
Vancouver, BC
'62 or '63 TR4 (formerly '64-ish TR4)