Hello Mark, I am not sure it is like this.

The sunburst one 510.523 has the rectangular-link one as a vast rule - I've just seen one with the Jubilee one and it looked a lot like a 510.511 that had been stripped bare of its coating (i.e. a 510.511 "turned" into a 510.523 with a heavy hand ;-)). Pay attention the links of this bracelet are much thicker than the flat-band one that was used on the 510.500 of the same period - and though it certainly does not feel heavy, it is less lightweight than that.

On the other hand, the PVD-coated 510.511 always came with the Jubilee-type: the one you put on sports a flat-band bracelet that was intended for the 510.501 and in fact risks scratching the watch head. This very specimen is indeed a one-off, and a very notable one considering its source ;-) (actually if the owner had not been so notable I'd have dared to say an 'error'!)

Surely lots of Heuers have donned different bracelets over time and even in the same time, but the L5100 Carreras do not seem to fit here: for them it was like one reference - one bracelet type.
What is certainly true instead, as Chuck pointed out in his seminal Carrera article, is that the 510.523 are available with both Heuer and TAG-Heuer clasp, whereas we only find Heuer-signed clasp for the PVD sibling. Not a surprise, as Heuer was already in the infamous parts bin period of its glorious history - the part whose output I like most of all, btw!

The period catalogues shed no light alas: I own two, 1984 and 1983, but they do not show the bracelet codes.
It is a fact that in catalogues both references always have the Jubilee-type one but consider they also miss the tachy ring and in one of the catalogues are even reported as waterproof up to 100m (which they are not, it's 33m only).

Cheers,
Fabrizio