Those are 1904 Cagneys from the St. Louis World's Fair. The gauge is 23 inches. The 18 is rebuilt but the 17 looks much like it did at the fair. I imagine the 18 will be down for some time with boiler work.
The diesel train is a 1939 Ruth. The locomotive weighes three tons but only the back truck is powered.
BTW a 2-6-0 coal-burner will be on line at Tiny Town next year. It is being rebuilt. The Occasional Rose runs Saturdays Sundays and Tuesdays. Its maximum tonnage is three cars plus the caboose.