$12 for two of those steel plates from SendCutSend, the blanking plate is even cheaper.
I made the bottom radius a bit larger after the test print; fits the block, a few pumps, and some gaskets fine though.
Shape is asymmetric mostly so I remember that the bottom hole is a bit offset, though I could have just oversized/slotted the hole. I remain suspicious of mechanical fuel pump sealing after one dumped half a quart into a new starter.
The last two files are DXFs, just download and manually retype the extension from ".gif" to ".dxf"
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