I know that some people have bred sterile line mos with leus, so you definitely have to keep an eye on lineage.

I am so excited that you guys are getting leus! When I first joined the glider world, they were still pretty rare and very expensive here, but have come a long way since. I hope that you guys have the same luck without any trouble. As long as you get a good size gene pool into the UK and people don't start shrinking it by breeding leu to leu, I think you should be fine.
I honestly never ever thought I would have a leu as they are still close to $1000 USD to purchase, but a very special lady listened to a few angels when she asked them who deserved a leu (who would be a good home for one and who could never afford one on their own) and they both said my name. I feel so extremely blessed that this wonderful breeder had an older leu joey whose original home fell through and she let me have my Seri for the cost of shipping her to me and let me pay her that back a little bit each pay check. My Serendipity is so beautiful and so sweet! My parents love their grandgliders, but my dad grumbles sometimes about them and when he met Seri, he said to my mom, "Can I have one?"
I also never thought I would have a mo, but once again, a poor older mo girl had bounced around home to home and her original breeder got her back and then twisted my arm (almost literally!) to take her in as she just couldn't find her a good home. That breeder is a very good friend of mine and has been since I first got into gliders. I am truly blessed and although I do not wish our current economical struggles on anyone, I do hope that it comes to the point where you guys all are able to get your dream gliders easily!