Standing at the front door, I took this first photo after I got off the bus. Excited to see something inside, anything at all--I'd never been able to see anything through the doors. So, these light fixtures and what look to me like maybe bank teller stations tickled me, big time.
Next I walked to the south end of the building to look in the first window there, after I walked around the corner onto SW Stark. I like the perspective of this view which shows those light fixtures and the counter as seen through part of the brass metalwork along the bottom of the arched window. The juxtaposition of the light fixtures with each other intrigued me. 
Curious and still not satisfied that I'd seen all I could see, I moved a step or two and took one more photo through the metalwork on the window--this one. I believe I saved the best for last. Look at that curved counter! The metal supports of the light fixtures! Well, it looks like metal to me. And you can tell that someone's been in there and left a chair and a piece of equipment. Left the lights on, too, thanks be to the architecture-lovin'-gods!
A vintage photo of the building--on the back it says "View looking Northeast at the corner of 6th Avenue and Stark Street showing Old Bank of California Building." and "Bank of California Building (Old), 330 SW Sixth Avenue, Portland, Multnomah County, Oregon, 3 of 8, Curtis Finch photo 1977. West and south elevations. Fletcher, Finch, Farr & Associates, 920 SW Thirteenth Avenue, Portland, OR 97205." From the National Register of Historic Places application for the Bank of California--I could not find the photos online anywhere except in the PDF, so I took photos of the photos with my camera because the thought of not being able to share them with you saddens me immensely. Please do not copy and paste this photo. Thank you. Oh, by the way, notice that curved-topped structure at the right corner of the building--that's what all of the mass transit stops used to look like downtown, on the Transit Mall. I miss them and their shape immensely.