I don't know the sizes of clausing lathes by the model numbers...I was assuming yours was a 10" swing, but the more I look at the pics I'm thinking its bigger than that. Bigger isn't always better when your buying a chuck. Don't get one so big that you can't open the jaws up without hitting the bed or cross slide. If it's a 10" lathe I wouldn't want anything bigger than an 8" chuck. If it has a larger swing then maybe a 10" chuck would be good choice.
Chuck
Chuck