Sean,
I have seen records of Franks Harris building:
- Real Club de Campo de Malaga (also known as Parador del Golf, near the airport). 1925-26 and 1930
- Pedreņa, in Santander, 1928-29
- Tablada, in Seville, 1923. The course no longer exists
- First remodelling of Puerta de Hierro in 1930-31. Not sure if they were also responsible for the original construction of the course in 1914.
All of them Colt designs. Unsure about their involvement in San Cugat, the other Colt course in Spain.