Me again. This is the older style of gasket, I remember using this style on a twin cam escort I owned in the '70s. http://www.ebay.com.au/itm/171698563773?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Installation is a bit more finicky and involves the use of some permatex #3 (or similar), as many clothes pegs as you can get hold of, and an overnight to cure. But from memory, once set, works quite well. I'm thinking of going back to this type, as the rubber channel type of seal has a habit of extruding itself out of place.
Robert