Before I re-did mine, I put both bearing races in the freezer over night. (I have a bearing in place of the Railko in mine). They press fitted fine. Just used a race insertion tool I got a couple of years ago. And tapped it in with a hammer.. The railko bush should sit flush with the bottom lip. If there is a gap, there is a problem.. I've attached a photo of one that's original. Sorry about the focus on the photo, but you can see how it should look.
Wolf

