Return spring on clutch linkage

[Brian]

Has anyone ever seen a supplemental external clutch return spring on a 65 GS?  I am working on James's car still and there is a spring hooked through the cotter pin hole at the lower z-bar end of the adjustable link.  The other end is attached to a bracket that is attached to the engine by one of the starter mounting bolts.  The bracket looks production like and not something homeade, so that is why I am wondering if this is some kind of dealer retrofit kit or something?

[65GS]

There has been one on my 65, 4 speed conv. which I purchased in Nov. 1969 . Dealer installed ?. Works and never thought about it.

Al

[Brian]

It is definitely not shown in any of the 65 service manuals, including the 65 GS manual.  All the manuals show is the torsional spring around the shaft, inside the flywheel housing.