Watch some early episodes of Hawaii 5-0 from the 60s. They constantly had Asian characters played by non-Asian Hollywood actors. Both Montalban and Mark Lenard played Japanese with fake eyelids.
On the other hand, I gather that since the show was actually shot in Hawaii, they did feature a fair number of actual Asian or Pacific Islander actors, certainly more than most shows of the era.
They did indeed. But in the early seasons (I just finished a complete rewatch of the the series, one ep a week over the last 5 years!), it seemed that any MAIN story character was usually played by a non-Asian TV actor like the above-mentioned fellas. 2ndary
parts were often Asian TV actors like Phiilp Ahn or James Hong. Background actors were often local Hawaiian talent. Naturally there were exceptions (female Asian parts were usually female Asians like Nancy Quan or France Nuyen). In later seasons it got better, but early on there were a lot of fake epicanthic folds on display!