The current article says the following on the AE-1: It was one of the first cameras of its time to offer full-aperture TTL metering.
While I think highly of the Canon AE-1, I don't think this statement is true. In 1976, a number of cameras had preceded the AE-1. The first few that come to mind are the 1966 Minolta SRT 101, the 1971 Praktica LLC and Olympus FTL. All of them had full aperture TTL-metering. There were even earlier Canon cameras using it, like the 1972 Canon FTb. As I understand it, the 1971 introduction of the FD series lenses allowed full aperture TTL metering.
a good source on the subject:
--driesvandenelzen 15:23, 4 September 2006 (EDT)
I'm afraid you have not given credit to the first SLR with Full Aperture metering, the Topcon RE of 1963. In fact I think you will find a considerable number of the bayonet mount makers went "open aperture" in the 60s. The "screw threaders" were slow to respond - Yashica & Pentax in particular, but as you say, the Olympus FTN was the first screw thread lens mount with Open Aperture metering.
Alpa is often credited with displaying a SLR camera with the first TTL metering, but in fact the 1960 Photokina Pentax Spotmatic prototype was the first on public view in an SLR. However it was Topcon that got its system to market first (April 1963). Alpa was, as understand it, stopped down metering anyway.
The very first example of TTL metering was the 1957 MEC 16SB, whose catalogue I have in front of me: "The MEC 16B is the only camera in the world that brings you the ultra convenient feature of the built-in fully coupled automatic exposure meter with its sensing element located at the film plane where it counts"
They seem to be doubly unfortunate as they don't even get a mention here! Feinwerktechnik GmbH, Kamerawerk, Lahr Schwarzwald http://www.cosmonet.org/camera/mec16_e.htm refers
Next in line was the Nikon SPX rangefinder (late 50s): http://www.cameraquest.com/bookmag.htm
The first Auto exposure TTL metered camera was probably the 1966 Pentax Metallica 11: http://digilander.libero.it/aohc/selart05e.htm