If the shoes are "Kilties" then they will have buckles attached to the shoe by 2 press studs attached to the small butterfly-shaped leather strap threaded through the buckle. All "Kiltie" buckle brogues will have the same-sized buckle attachment so if you can't find the manufacturer try and get any old pair of the shoes and just pull the buckles off and replace yours. Don't get any of the buckles linked here as they will be no use to you. If you still have the pair off e-bay the buckles should fit OK even if the shoes are too wee. Take some glue to the press studs though. There is no reason why they ever need to come off and they seem to pop off fairly easily.