You've made an excellent signing in Mossy. I may be somewhat biased but I didn't see a better right back in the division last season.
As and out and out defender he's top class, where he lacks these days is in his ability to get forward to good effect. Strangely something that he excelled at in his first spell at the club before his £170,000 transfer to Crewe Alex. He should now be at or around his peak and you should get some very good service out of him over the coming seasons.
Simpson has made a major error of judgement here in my opinion. Mossy was a consistently high performer last season and was more deserving of a decent new contract offer than some. Instead he was offered a one year deal and a 40% pay cut, the lad has a family you can't blame him for looking elsewhere.
Our loss is very much your gain. Simpson has moved quickly to sign his replacement in Dean Holden, but in my view you have the superior player of the two.