The XCalibur would probably today be considered a medium-light to maybe medium oil ball.
I suspect you might need upwards of 500 rpms to be able to use on today's true heavy
oil, even if you sanded it..
The Cyclone mentioned above would probably mimic the X-Calibur's general reaction on today's oil conditions and patterns. It is a safe starting point. You will likely want to add a solid on slightly more oil-handling ability as a first option, IF the drilled Cyclone suits your style.
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