18 titles sounds like an extensive collection, and the titles you are after now are top shelf. Definitely worth checking with Mark at Child Amusements as he often carries these titles, and the ones he sells are shopped (cleaned, polished, new rubbers, new globes, new pinballs, tested fully working) which would fit your description of nice clean games. He is overseas at the moment but contact details can be found here: http://aussiepinball.com/index.php?topic=354.0

Good luck with your search.