Aah! Look what I just bought!
http://www.ebay.com/itm/121113874564
I've had a search up on eBay for one of these for a long time now. My yoke is fine, but the rear cover completely disintegrated, so I had to make a new one out of cardboard. This one has the rear cover intact! That's all I'm buying it for, really, but to me, the $30 it'll cost me is worth it (especially since I've never seen the cover separately, except from someone I messaged a while back who lost it before I was able to contact them). I also ordered a bottle of corona dope today to hopefully save my flyback with.