[Ron Ramirez]

Honestly...I've never had that type of shadowmeter open, but I would think if it is anything like the older ones (and the newer 1937-38 meters), that the vane should return to center of its own accord without the use of springs or any other help. Does the vane pivot freely? Sometimes they bind up, and then will not move freely.

I've only seen that type of shadowmeter on late 1936 model Philcos, and used as replacements on a few older sets. My 91RX has a shadowmeter like yours, but I know they weren't making them that way in 1932.