Teddy, the predecessor of CiU, Pujol's Pacte Democratic per Catalunya, won 10 seats in 1977 and the UCiDCC, which included the present-day minor UDC won 2 seats.
The curent-day Catalan nationalists are made up of two parties: Pujol's CDC and the smaller UDC. In 1977, most CDC and UDC ran separately from each other, the only time they did so. The CDC, which was unambiguously Catalan nationalist, formed the Democratic Pact for Catalonia and won 10 seats. The UDC, then divided between nationalism and christian democracy, ran with a smaller party in the UDC-IDCC and won 2 seats. The UDC-IDCC was actually the Catalan referant of the broader Spanish Equipo de la Democracia Cristiana (a coalition of 2 Spanish centrist parties, one led by Gil-Robles) which won no seats.
If there is such a thing as a "Catalonia Party", the PDC was that in 1977. As I said it won 10 seats.
Also, you should update your graph showing the seats won by HB and the Canarian parties.
