Great investigations men !
You should all know that after I send the pictures of the accelerator pivot to Carl this week, he replied with something like :" ... I'm confident you will figure it out Thierry" and now, who has solved the mystery dear Carl ?
You probably are correct that it will be part number 1365.67.717
The curved form was probably needed for avoiding the protrubing heater body.
From the 608 catalog I learned that the 1365.67.717 accelerator pivot was introduced from Berlina 1488.06501 and from the first Ti on and guess when the protruding Berlina heater was firstly mounted ... indeed, from the Berlina 1488.06501 and from the first Ti on !!
A last detail is that the distance between the two aluminium supports is a lot more than on the other levers. This can also be seen comparing Greig's pictures in posts # 9 and # 11.
Carl, if the accelerator pivot in Greig's post # 9 is original, it must definitely be the 1365.67.705 as mentioned in the 10/1956 catalog. I don't think there was already a picture of that one ins't it ?
Thanks to you all for showing interest and resolving this little mystery.
Rgds from Belgium,
Thierry