I am restoring a '47 Farmall H and would like to return everything to original. The tractor now has the friction disc governor control. My parts manual shows a governor control sector and handle with the sawtooth cover. Was the friction disc control an add on aftermarket control? The friction disc will not hold a selected setting without creeping back. Should I purchase a replacement friction disc and spring or look for and install the sawtooth control? Will the original governor control rods attach to either type handle? Also, the exhaust manifold appears to be a replacement. The carburetor mount has elongated mount holes I presume for different size carburetors? Are there any original manifolds available or are most originals prone to cracks, warpage etc? Thanks for any infomation and advice. The information and knowledge from everyone on this site is excellent.