I only know about CRGS (which isn't much help to you!) but would suggest you contact the school(s) you are interested in directly as I do know that CRGS administer their own tests & suspect that the others probably do the same.
Could try looking on their websites (Crgs have details under the admissions section on their on-line prospectus so again just extrapolating
Or you could try contacting CSSE (they close during holiday so you might still get them) but I think they only deal with 11+
Hope someone more knowledgable comes along soon