are those RZ cylinders?? In the second pic it looks to be where the powervalve would go...
About your question, since on the oem banshee cylinder the aluminum is cast around the sleeve, so therefore they actually bore the cylinder until there is no sleeve left then press in the new one...my opinion on this is i think it would be risky, seems like there is not going to be much support left after the stock sleeve is bored out, look like the actual cylinder itself might just break when pressin in the new sleeve.
But your best bet is just going to take them somewhere and see what they say like jbooker82 already said.