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the owner said they need be done in 2/3 weeks time but
i cant see that being right there wool is really matted and dirty and are getting bugged with the flys now>>>
You are right Emma - they should have been done a few weeks ago and certainly before you bought them. The risk of them having been struck by the flies is quite high, especially as it sounds as though the previous owner didn't look after them very well. Fly strike is serious and if not treated the animal can die, which is why I suggested you bring them in and look through their fleece for maggots. The maggots eat into the flesh of the sheep, and they can die of infection and toxic shock. If at all possible you shouldn't wait for your shearer to come, but have a look straight away. Perhaps there is someone on here who can help you, before a shearer can get to you. As you have found, Hebridean fleece can mat tightly, especially when it's warm with heavy rain, and all sorts of things can be going on under the mat.
It's probable that they weren't wormed either, so if you didn't do that when they arrived it would be a good idea to get them wormed too. Your vet will advise the most appropriate wormer to use.
Feet and a general check can be done once the shearer gets there.
What a bad beginning for you with your new flock. Hebs are wonderful and once you have got this sorted out you will love them