Hello Nathan - this is a nice piece as a beater, the case has had its (more than) fair share of knocks and the chrono hands are discoloured to a nice but weak orange.
The pewter PVD is the second scarcest in terms of availability, behind the 510.502 green PVD I'd say.
Consider it will be quite impossible to restore this PVD colour - some are able to recoat in black, hardly anybody in this grey or green.

If I were you I'd ask an additional picture with all chrono hands reset to zero to check this feature, often central hands do not align properly and not many watchmakers are able to properly service a L5100 (see a post of a couple of weeks ago).
The warranty and instruction booklets are a nice touch as well is the box, but I don't think the latter is the correct one, these used to come on the 'cubic' blue one or the TAG Heuer one in the very last days.
All in all, if the watch were on its own I'd value it around 800 EUR, and throw in an additional 100 EUR for the additional items.
For comparison, Heuerboy has a very clean one, almost perfect for sale.
Cheers,
Fabrizio