It looks like the sweep generator works. I think the marker will have to get sharper. Where are you injecting the marker? If you are running it all the way through the IF like the sweep, you have to keep the level low. They are usually bloblike, but yours is so bloblike it's almost unusable. Maybe it would sharpen up a little if you put a resistor in series with the marker output?
One part that confuses me, youre injecting sweep and marker at IF frequencies, but at the antenna terminals? I would think that if you injected at the antenna, you would have to use a TV channel frequency, and that the fine tuning would affect the results.
I wouldnt run off and buy a sweep generator just yet
John
Oh, one final thought... I dont really know, but with split sound it would seem to be a 50-50 chance whether the sound or picture is on the wrong frequency.