I would take the ewe lambs out pronto. Soay lambs take a long time to mature, which means that if they do get in lamb then they are far from fully grown, and growing and rearing their own lambs could be too much for them and affect their long term health.
Your ram will be the problem - again, I would take him out and let the ewe lambs back in after a month. It will stress the ewe lambs to be away from the flock, so the sooner they return the better. They also learn about lambs and motherhood from watching the ewes give birth. The reason the tup will be the problem is that you can't keep him completely on his own, unless he's only a fence away from the flock. Soay rams jump, amazingly high, so unless you add taller posts to your fencing and add another roll of mesh above the existing one (to give a 2m high fence) there is always the risk he will jump back in.
Our Soay rams were awful when left in with the ewes at lambing - they pawed and butted at the ewes when they were on the ground trying to deliver, so the ewes had to get up, not ideal during delivery when they need to push and proceed with labour. Now we never leave male sheep (including wethers - they're just as bad) in with the ewes long term.
A possibility would be to board out your tup with another sheep keeper who has a tup or a bunch of tups, and room to keep them separately from the ewes. Soay tups can be really aggressive towards other tups, so big fluffy, hornless companions would be best - the Soay would bounce off