Maybe a fine car body filler will smooth it out? Bill and Aaron can probably advise which brand to get in the USA - it'll be the type used for filling small scratches in paint work. Or leave it as it is, and call it 'ground handling damage' !?!
For nose weights, use something like 'Plasticine' (kids synthetic modelling clay) with either small lead fishing weights, or air gun pellets embedded into it. This should not cause the plastic to deform, and the lead weights, held in place by the 'Plasticine', will provide plenty of nose ballast.