if it's grinding when driven it proably beyond a recon.
recon / overhaul generaly means new seals, bearings and syncro mesh. and just inspect the gears damaged gears can mean it gets uneconmoical to repair very quickly,
damage to any gear that intergral to one of the shafts will usally write the shaft of, when you consider it's mate is then scrap by default it runs up the £'s quick