The adaptor that is on your gun is a variation of the adapters that were originally made and used to mount an 08 on a Swiss tripod. The one I see on your gun was made for Firepower Internatiional, Christian Cramner of IMA's Brit Militaria import business in GB. If I recall correctly, the Turkish 08s that FI imported into GB were adapted to Finn mounts with that type of jacket bracket, which was elevated, and using elevation parts fitted to the traverse.
Dolf Goldsmith originally imported the Swiss tripods and had adapters made for most of them to fit the 08 guns. The adaptors were copies of the orginal ones made for the same purpose. These adaptors were very short in height and fitted the traverse without adaptors. FWIW