O, those are some excellent close-ups of the Lacôte. The condition is

, someone(s) kept it in their wardrobe/under the bed all this time! And that case! He was a fantastic builder, and though he was based in the Romantic guitar tradition, he worked with customers and did a lot of customization, the collaboration with Coste being one example.
Lacôte certainly had easier access to good quality materials (check that one-piece flame back!), unlike Torres, for whom it was a problem. I don't know if anyone's written a book on Lacôte (or Panormo, for that matter), would be a grand thing. Romanillos' book on Torres is still the standard, though much has been learned in recent years (someone should also make an online database of Torres’ instruments, there’s still occasions when a previously unknown one is found). It’s an interesting read nevertheless, and I’d recommended to any guitar geek, though it’s hard to find.
The simple aesthetics was something that began to be increasingly the case in the 19th century - guitars were coming into the hands of proficient players and composers, and these serious chaps (perhaps influenced by viol players) were looking for instruments which had minimal ornamentation, and were made with optimum sound production in mind. Guitars with lots of inlay and marquetry probably were seen to be more pieces of furniture than musical instruments.
Yes, Coste should definitely be included among important extended range players. I guess guitarists know George Van Eps and Lenny Breau as 7 string players before Steve rocked it up, but some of these 19th century guys were certainly ‘with it’. I mean, the Germans and Austrians were building and playing the Schrammelgittaren with up to 13 strings. When Torres, subsequent makers and players championing that guitar type came along, everything else went by the wayside, so we kind of forgot about extra strings and things like baritone, terz and tenor voiced instruments in the mainstream classical world (still strongly maintained in viol and mandolin world, however). I don’t think there’s a guitar ensemble out there where people are playing these instruments, everyone plays a regular guitar, kinda boring! I read an interview with the Austrian builder Daniel Zucali recently, and he talks about this, and one reason he builds baritone, terz, extended range etc. – he wants players and composers to (re)embrace these other voices and ranges to create a real ensemble, like a guitar version of string quartets/quintets. I can get behind that.