If you are a good TIG welder and have lots of time and PATIENCE you can put it back by welding a little at a time.
You may have to rough machine and finish grind it a couple times to get it right.
It's not cost effective to have it done but for a hobby project it can be done.
Glenn, I think he is referring to the rear of the crankshaft. He probably has one where the slinger was machined out to use one of the infamous new and improved seals that never do.
I watch the slinger get replaced by using low heat and soft solder. It came out very nice. Since it only needs to sling oil, it doesn't need to be a hard steel or other hard metal.