The axles that I've worked on had more play due to the channel that the axle fits into being spread apart than wear in the pin. Check to see if that is more the problem in your axle. There is no easy way to put in a larger pin or weld on new bushings to go back with an original pin. It's certainly doable, but not so easy. You might be able to tighten it up by squeezing the channel together with a 3/4 inch bolt and a nut. that might give you the results you need with just replacing the pin with a new one. Some others here have actually used a 3/4 inch bolt in place of the pin, but I've never tried that.
Post some pics of what your axle pin bushings look like.
And welcome to the forum!
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