125-200cc wre cylinder honing quey

hello out there! I have a random question to ask. I was looking through paperwork today regarding my WRE 125 and I read the words [cylinder honed, fit new piston]. Now I think honing is where you replate the inside of the cylinder, and this is what the piston ring rubs on as it goes up and down right? Well I thought, surely if they have honed the cylinder, would that mean it is actually slightly BIGGER than it was as a standard barrel? And if that was the case, would that mean my bike is not a 124cc now / 125cc, but maybe a 127, or 128 cc? Sorry if this is a stupid misinterpretation but I am curious to find out.
Also, how costly are the 144 top end kits for the wr/ wr models, not including fitting? And where can I find one? my local shop said ebay but I can find nothing