1947 Rear Axle Worn Down

[Sprattman]

My 1947 Ford Super Deluxe won’t move when in gear and I noticed the left rear wheel not turning very well. Pulled off the tire and the drum and found that the pin/bar in the axle end had completely worn down and being stripped down to nothing was the issue. I am starting to do research to understand the steps to success. Is there any way to fix this or is it a full replacement of the axle or maybe it’s just the left side to be replaced? Starting a new thread on this here to get some insights and tips from the Ford Barn community to do this right. The inside of the drum itself where the pin/bar slots into looks to be worn down as well. Pictures attached show before and after.