Window regulator question

[wrndln]

I have several 3 mounting screw window regulators I have acquired over the past years and never knew what they were used on, shown in the picture below. Most of the window regulators I have, have a solid arc part with 3 quarter size holes in them. This style regulator only has a thin arc strip with the teeth on it. Maybe it is a later regulator used for 30/31 cars, but I don't know, as I am a 28/29 person. I assume they are interchangeable on most Ford produced passenger closed cars (I know Briggs and Murray regulators are different). If anyone knows what this style is used on, please post a response.
Thanks
Rusty Nelson