The buyer isnt on social media? You didn't take note of his or her address or phone? Sorry just spit ballin here. I know what you're going thru, I sold my dodge 2500 diesel and miss it every day. Sold it 9 years ago. Crazy how attached we get to items haha. Try calling the local DMV to do a vin...
Wish you were closer, i'd give ya a hand. I did a full power steering system refresh last winter. Placing the gear in an oven for a while could help also. The key on the shaft has the round part that goes into the opening facing towards the shaft. So the flat part is exposed. A new gear from...
Could be that the gear is not fully seated on the shaft. I took measurements of the gear to pump housing gap before and after. Try using a socket and try to tap the gear on further. Good luck!