Jeff - looks like yours is older. The bridge number you noted 450617 is correct and the back number is 57706 in this one. They could have been made in the same year?
A note about opening the back - this one is also very tight. I almost always regrind the opening notch on snap backs so they can be removed easily. You can see where this was done just below the serial number on this back. This one originally was all chewed up from openers that were not used properly plus a slot that was too small to get an opener into. I use a 25mm course sanding pad on a Dremel tool to do this - works great and only takes a couple of seconds to do. The angle is probably around 10 to 15 degrees. Had to do the same for the bezel - it had no notch at all. Craig

: Wow . . . what a beautiful old Heuer!!

: Here's my oldest Heuer chronograph that is powered by the V72;
: notice the "flat" Heuer logo. My watchmaker told me
: that this one has a very early V72 movement.

: Mine has SN 450125 on the movement; appears that you also have a
: 450xxx serial number on the movement [maybe 450617?]; so yours
: may be slightly younger than mine. Can you please confirm your
: SN? I'm not sure about the SN inside the case-back; this one
: does not like to be opened!

: Jeff

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