One of the things in textile production that are underestimated, as a rule, is wool preparation. Quite often, spinning is the first task that people think of. There is, however, the tiny little fact that fibre preparation has a rather large influence on how spinning goes, and is thus important. It's also time-consuming, as everyone who has ever hand-processed some fibre for spinning will know quite, quite well.
Wool fibre prep starts with shearing the sheep or with the shorn fleece, depending on how you see it. The dirty fleece needs to be cleaned at some point, and the fibres sorted and prepared for spinning.
It is technically possible to spin the fleece just as it comes off the sheep, with all the dirt in. This will be easier if it's a good-quality fleece that is not too dirty (or if the sheep has been washed before shearing, which is an option as well). I've spun dirty fleece, and I confess that I'm not thrilled by it.
Whether your wool is clean already or not, you can prep the fibres by teasing them apart with the fingers as the most low-tech, low-time option. Next step up is aligning the fibres in some way, which can be done today using either combs or cards. As far as I can tell from historical sources, the Middle Ages used the wool comb only until the Great Wheel starts to turn up, which is when we also get evidence for cards. There's some textile tools found at Hallstatt-Dammwiese in Austria and Liptovska Mara in Slovakia, dating to the Late Iron Age; they were flat wooden boards with holes, and thorns were placed in those holes. Whether they were used for roughing up fabrics, preparing flax (hackling boards) or for preparing wool is unknown, though. (Pics and references can be found in Grömer, Karina. The Art of Prehistoric Textile Making. Wien: Naturhistorisches Museum Wien, 2016, p. 72f.) Combs were found in prehistoric context as well, and it's relatively safe to assume that they were used for fibre/wool preparation.
Wool combs, as they are shown on medieval pictures, are something that can be expected to only rarely turn up in archaeological evidence, due to the usual two reasons: They are made from perishable materials (wood and iron are both not very talented at surviving burial), and they are rather nondescript if falling apart. Added bonus: For something to be findable in publications, it has to be a) identified and b) published (where b usually requires a). So if some weird little piece of wood with a row of holes in it gets found, and there's no or little trace of iron in the holes, it might not get identified as a wool comb fragment, and thus not get mentioned anywhere.
This, by the way, is a problem not limited to textile tools; it's a general problem in archeology. Me writing this is also not intended as criticism towards my digging and publishing colleagues - I do know that they are all taking a lot of care, and trying hard, to identify as much of the weird bits and pieces that are found. Archaeologists working on a find complex look at lots and lots of images and lots and lots of publications of other sites, searching for comparable objects (also for dating purposes). There's also the option of asking colleagues, of course, something that is done as well - and showing mysterious things at conferences.
This general problem is a phenomenon of there being so many, many, many things in daily use and daily life that it is impossible to know them all. Just take a look around your home, or a look around a workshop of some craft that you are not familiar with, and try to imagine how hard it would be to identify things that are broken in half, or where there's only a fragment left.
And now I've rambled off on a tangent... we'll return to wool combs tomorrow.