Increasing timing pulley bore size from 3mm t0 3.175mm

[black5f]

You need to increase the bore to 1/8 inch? You may just get the end of a 1/8 a taper reamer in ... but you want it to run true, ideally do it in a lathe and make sure it's true ie true up with 3mm shaft in. So, do you know any one with a lathe and a nice long 1/8 taper reamer (apart form me!)?
Tom