Finally got around to it. Easy peasy using the previously mentioned Excel flashing. This one fit right under the ridge cap. A few screws and a bunch of silicone to finish up. Be aware that it doesn't fit Supervent pipe anywhere near tight. That gap took a bunch of silicone to fill. It is also pretty short, and since this is a weekend place, I am anticipating snow up past the flashing. We'll find out how good I did sealing it up. I have some pics from webby3650 from one of his installs, showing how he cut it into the roofing. If anyone is interested, I'll try to repost them.