Need a dovetail hollowed out on the underside....

I need an odd dovetail for a Chinese EQ mid size mount. It's size is close enough that Vixen sized dovetails will work. The mount has a bolt head that sticks up into the place you put the dovetail. Most dovetails are solid bars or have some metal work that would hit that bolt head. What I need is one that is hollowed out on the underside, like the one pictured. Or something similiar.

Anyone know who may have something like that?
Thanks,
Steven

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Can you just drill yours where the protruding bolt is? Or is it a larger area?

Alex