10mm trains and trams should be readily available in N gauge railway ranges. Also worth a look on eBay for Del Prado models, these were a collectible range of static models, that are great for gaming.
Thank you Fred!
They're a lonely looking lot so far, but I should be making more bases eventually- these are seen on one of the dropzone commander boards. They are a bit featureless, and they came out quite dark and ominous, but ominous is ok for zombies I guess! More pics when I eventually get more done.