TR6 72 TR6 Commision Plate and location?

I have a 72 TR6, commission #CC81610 UO, build date APR 72. My question is this, which is the correct commission plate for this car and where does it go? Most references like TRF show an earlier commission plate (without the words "Passenger Car" just above the paint and trim code) and list it as mounted on the wheel well. My car is complete numbers matching and verified through British Heritage, that being said the commission plate is mounted to the drivers rear post and the plate itself is the later one used from 73 to 76. I know the spring of 72 was a change over period for production and the 72 wound up with pieces from old and new design. Would like to hear from some 72 owners or anyone with the knowledge of what they have on their car. I need to stamp out a new plate and I'm trying to get it period correct. Thanks in advance.

That driver's side (LH) B-post is where it should be. Of course, there also should be a tag on the LH side of the windshield frame with the same Commission number. I'm a bit surprised at the TRF reference, as they typically are more accurate than that. AFAIK, all 1970 model year and later Triumphs had the commission number plate on that B-post. As to style of plate, I can't say, but given the manufacture date and statement of compliance with Federal reg's, I'll assume it's correct and original.

Thanks Andrew, I do have the tag on the windshield post and it matches. From what I can tell the commision plate changed over to the later version somewhere towards the end of 71 but it does not match up with information from various sources and suppliers. It's not the end of the world but trying to keep everything correct as possible. Hopefully more readers will have some information.