I'm in a conversation with Wendy on The Crag regarding the new route she has written up to replace Yossarian. Unfortunately I can't find a way to add a photo to the conversation on TheCrag so putting it here instead.
This is where I have always thought the start of Yossarian goes. I've started it this way twice. I once scrambled up the gully and did the much easier, shorter and worthless approach from there.
The description in the 1969 guidebook described the start as climb the buttress a couple of feet right of Toccata - that's no more than a metre right of Toccata. There's no mention of scrambling up the gully which is what you'd have to do to start any further right.