I have a Metz 60CT2 which does permit TTl metering with certain cameras, including my Olympus OM2n or OM2s.
It works in conjunction with the right cord - an SCA 520 if I recall correctly.
Other Metz flashes use the SCA 300 system - the flash takes interchangeable connectors and/or feet, which when combined with the right cord, also permit TTl use with certain cameras.
In my case, the Metz manual for the flash describes how to use it with the connector and my OM 2n/2s.
Do you have that manual? EDIT: here is a link: http://www.metzflash.co.uk/pdffiles/45CL4_e.pdf
EDIT: and here is a link from Mike Butkus' site for the SCA 300 system manual: http://www.cameramanuals.org/flashes...tz_sca_300.pdf
By the way, the compatibility chart I've found doesn't even list the SCA 346 adapter you refer to? http://www.metz.de/index.php?eID=tx_...71fda8fc6247a3