Harald Petersen was a Danish luthier who had moved to the UK and sold his instruments through the Spanish Guitar Centre in London (established in 1952). Harald died in 1968 but his sons (who worked with him) carried on making Harald Peterson guitars for a few years after that. He made 3 models: A, B and C. The B had rosewood sides and back, the A had maple side and back. The C was the most expensive - made from the same woods as the B but with fancier fittings and finish.

Source: Delcamp Classical  Guitar  Forum (28 January 2019)