Do I NEED to prime it?

Easy-peasy to make a priming shaft for this: Get a 3' length of 5/16" mild steel round rod from any hardware store. Using hammer and hard surface (vice, old engine block or head, etc.), hammer the rod into a hex shape. It's easy to shape mild steel, takes 1-2 minutes, and the resulting hex will be the right size to slip into and drive the oil ump.