NEED 75 cb750f or 77/78 cb750K front brake caliper

I'm in dire need for a 75/76 cb750f or a 77/76 cb750K front brake caliper that has a working bleeder valve.
The earlier K model calipers are very different and the cb550 calipers look exactly the same as what I need but are smaller..

If anyone can help me out, Id greatly appreciate it.. I could trade a bunch of stuff of buy it out right!!

Thanks
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