[cypher]

That sounds as though they could be great cages but I would be a bit worried about using contact paper, it could get scratched or chewed which may not be safe for your hams & the wood would lose it's water proofing, the best thing to use is melamine board which will keep the cage water proof & not provide anything to chew as long as no edges are exposed.
Alternatively you can use a non toxic paint like Plastikote water based enamel but if you aren't in the UK you may not be able to get that.
Other than that it really is a case of not having any edges that might be chewable.