Hi Claudio, I am really no expert on those late boxes and of boxes in general, so pls. take this with a healthy pinch of salt. This is my 2c, but pls. do collect further inputs.
Overall this looks more or less fine to me - yet some details are different from what is shown in official catalogues and we've seen from the red chequered boxes that indeed sometimes the devil is in the details...

Basically the proportions, the outside and the script look fine to me. My doubts are if it should also have additional scripts on the front lid, the Heuer script and shield on the inside of the lid and a different colour in the lining. If you take a look at the '83 catalogue from On the Dash here there's a box that has the same shape as yours in the middle:

http://www.onthedash.com/Guide/_Catalogs/1983_Chronograph_Catalog/83TFAZ1A.jpg

but this has a dark navy interior and also a "Swiss 1860" on two other lines below. Later catalogues on the website do not show any boxes unfortunately.
On the other hand, let's not forget these were the heady transition days of the "parts bin", where even watches were sometimes built up with different pieces, different hands, TAG-signed bracelets on Heuer watches and Heuer-signed crown on TAG-Heuer watches etc. - so it may well be that once their supplier of boxes ran out of blue linings for the boxes TAG Heuer could have accepted the white one with no script or that several box types were used together and some not shown in catalogues.

Furthermore, 5 or 6 years ago a well-known German dealer offered me a Lemania 5100-powered Carrera with a box exactly the same as yours. Same period as the pewter Autavia but a somewhat smaller watch.
In the end it looks almost the part of an '80's box such as the pewter Autavia: so it may well be, but no 100% certainty for me.
Sorry, no definitive answer here but I hope it can still help a bit.
Cheers,
Fabrizio