The TD was sold with a 1250 cc XPAG Type Straight-4 engine. It made 57 horsepower, which was not such a paltry sum considering the small size of the car.
Some of the features of this car include the hypoid geared rear axle and a Y-Type chassis, along with the T-type body that MG had already made popular with the previous decades. In the front, the car had independent suspension with coil springs. Rack and pinion steering was standard, which was unusual at the time. Its bumper were also uncommon on most cars from that period, although MG was already showing signs that they would be a car company that cared about driver safety.
Although 30,000 of these cars were made in Britain, only 1,700 of them remained there. The rest were exported to places like the United States. The U.S. versions were made at the factory with left hand drive, so no conversion was necessary.
In 1998, a company in Malaysia named TD Cars Sdn Bhd bought every intellectual property related to this car, including the trademark and the right to build new ones. Since then, they have been making the TD2000, a modern reproduction of the famed British roadster sports car.
These TD's, along with the TD2000 official reproduction, can be bought out there on the collector market, but it's easier if you know where to look. There are usually a few listed on eBay, so that's where I'd start. It's also a good place to sell a TD and avoid the mark down from retail you'd get from a used car dealer.