I've used a speedie sleeve to repair worn shafts etc like that but the problem here would be the potential distance of travel of the shaft through the oil seal. the seal might get damaged moving over the end of the sleeve.
all speedie sleeves I've seen and used would not be long enough, a long one would be great but the end of the sleeve would be noticeable, I guess a small deduction in any judging but worth it to retain an original part like that ?