Another confirmed 'Eyes Staring from a Portrait' sighting: WHO KILLED DOC ROBBIN (1948) - and it's in Glorious Cinecolor to boot.

When the kids first enter the creepy old house there is shot of eyes watching them from a portrait, presumably George Zucco's baby blues. Later one of the kiddies stumbles on the backside of the portrait and pokes his fingers through the holes, prompting the other tots to toss tomatoes at it. You do get a good look at what the backside of the portrait gag looks like.

Unfortunately DOC ROBBIN is listed as being released in 1948 which puts it a year past your timeline.

If you're an Andy Milligan fan there's no hope for you.