The R14R should fit. The Raydex shares were three bolt, and then later they added a fourth, larger bolt near the point. These 4 bolt shares will interchange, you just have to either leave out or cut off the 4th bolt. The shares for 18 and 20 inch bottoms had 5 bolts, but they would be way too big anyways.

Here are a couple of sources:

Shoup Parts
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Cresent Forge and Shovel Company
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