The BSA A10 series was a range of 646 cc (39.4 cu in) air-cooled parallel twin motorcycles designed by Bert Hopwood and produced by Birmingham Small Arms Company at Small Heath, Birmingham from 1950 to 1963. The series was succeeded by the A65 unit construction models.
The BSA Golden Flash, commonly referred to as the Gold Flash, was the first of the series to be launched in 1950. Painted in a new gold colour, 80% of production was destined for the United States. This resulted in long delivery times for British customers, who were offered the model only in black.
Although never designed as a sport motorcycle, the Golden Flash was nonetheless fast for its time and competitive with the Triumph Tiger 100, achieving over 100 miles per hour (160 km/h) in tests in 1950, and covering a standing quarter mile (400 m) in under 16 seconds. Its gold colour proved a marketing success, outselling Triumph’s Speed Twin and 6T Thunderbird.
It received updates throughout its model life. In 1960 it was renamed the “Royal Tourist” in the US. An alternator was offered as an alternative to the dynamo from 1961 to 1963, the last three years of production.
https://en.wikipedia.org/wiki/BSA_A10_series

The core engine was acquired in the UK. The parts needed to make it a complete engine came from Australia, Canada, the UK, and the USA. Other miscellaneous parts were sourced in countries not mentioned above.
1954-1957 BSA A7 A10 Parts Book