We have a set of 3 collages bought from Hong Kongaround the 1970’s. Do you know who the artist is please?
Just so that there's no confusion about the character shape in the seal, which is 「陽」 and not 「揚」. See the third shape below:
In general, the name of the artist is written in the seal. In the photos you took, the font of the seal is 小篆(Small Seal Script /Xiao Zhuan, an archaic form of Chinese calligraphy). Since it was a little blurred, I'm not 100% sure but I think its 沈扬, not 沈阳. I tried to google this person's name, but unfortunately, I didn't find any useful information about this person/artist. In my opinion, there are two possibilities: maybe he/she is a well-known artist and since it's a picture you bought 50 years ago. It's hard to figure out who he/she is. Or, as 水巷孑蠻 said, its just a picture from “product line“, even the seal may be not true. But this is still a beautiful picture with memories, isn't it?