Howard, I own a Six-20 Brownie Junior. It's likely that your viewfinders are caked in dust and dirt. You can clean them by simply popping the front plate of the camera off (may require some wriggling and prying with a small screwdriver), taking a cotton swab with some cleaning stuff (water will do though) and wipe them clean. They should then be very clear.
Ah, I see that the Starlet is the Uk export. A rebadged Brownie 127.