Thailand would have an added dimension of Japanese-built locos. Looking at a display of old b/w photos at Bangkok's main station a few years ago, there was American, German and a few British locos (possibly ex Federated Malay States Railways?) in evidence. Also never knew that they regauged from standard to metre gauge.
Most towns on the rail network have 'stuffed and mounted' locos on display, including at Kanchanaburi, the place that inspired the Bridge on the River Kwai. They had a Garrett, a couple of NBL 4-6-0s, a Japanese (2-6-0 I think) and a Japanese railcar adapted from an army truck.
Burma still had some nice old diesels on VERY rickety track and a red/white railcar that wouldn't look out of place on the wee Donegal! And Cambodia had Chinese cast offs with a few Franco Belge kettles either on display or stored in sheds. Some rolling stock was either Aussie built or had components from that neck of the woods, saw 'Sydney Aust.' on one wheel bearing cover. The one passenger train I was on was hauled by a Czech shunter still in Czechslovakian livery and company plates!