[midoridensha]

This is an addendum to my other reply to you. I only briefly googled for this model, but my guess is that it's an older model. It should be possible to find a newer product (either from Tektro or better yet Shimano, which uses the same kind of mineral oil as brake fluid so you can probably reuse your lever if you want, if it's the caliper that needs replacement) which is compatible with this system's mounts. You'd be better off doing that than trying to get an exact replacement: newer designs are usually better anyway, plus they're frequently cheaper since they're current production.