As long as I have been paying attention to the IA vendor's rotating selections, it seems like the only collectible fragments he's had for sale have been for things which drop either in public dungeons (e.g. pieces of the Dwarven Theodolite or the Thrafey Debutante Gown) or in the archive itself (e.g. fragments for the Maligraphic Mount). I hope that some day, the good filer will branch out and sell other types of collectible fragments - namely, the Heavily Played Tribute Cards and Scraps of the Spearhead's Colors that may drop from Tales of Tribute rewards. I played Tribute rather extensively back in the day and have yet to finish either of those achievements. I am sure that there are similar aspects of the game which rely on the whims of RNG for earning collectible fragments which could cycle through the IA as well, but Tribute is the one that comes immediately to mind.
While I am talking about Filer Ool's wares though, can I also request that your team put more thought into the kinds of leads that he has for sale? Don't get me wrong, a lot of them are great - particularly leads for mythics or furnishings which drop rarely. But all too often, one of the two leads that is on the table each week is for something like the Ebon Dwarven Wolf or the Druidic Provisioning Station. The latter in particular is a complete waste because those leads are in guaranteed locations: you can literally look up the furnishing on an online guide and go from point to point in the zone and you will have every single lead. No RNG is involved at all. And in the case of the wolf mount or the Blackwood tapestry, those are collectibles so the leads for them only ever need to be farmed once, ever, per account. I would be much more excited if the IA vendor offered more leads that drop in Cyrodiil or BGs so wimpy players like me would have alternate paths to completing those mythics, etc.