I've breadboarded this up and it sort of works. I think the problem may be the extremely short leads on my 1uF cap, or else the fact that I don't have any 3.3MΩ resistors and substituted with three 1MΩ resistors in series. I do have six 100kΩ to make up the .3 on each, but I worried I wouldn't have the room. Time to rewire!