We've searched the internet and found the largest collection of On30 Scale trains for sale is on eBay. Below are the listings for 'gauge model trains'.

7008 7 DD51 500 medium term low temperature models N gauge by CATO
7008 7 DD51 500 medium term low temperature models N gauge by CATO
$85.79
Time Remaining: 22d 21h 34m
Buy It Now for only: $85.79

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7008 7 DD51 500 medium term low temperature models N gauge by CATO