a preliminary note: using a scrap of vinyl convertible-top material from a local auto upholstery shop (free from its scrap pile), affixed same with some goopy stuff called "elmer's stix-all" which bills itself as a "hi-tech adhesive" (bought at a wallgreen's). glued the patch from the underside, then infilled the slashed area on top with thick layer of the stuff. not pretty but seems to be holding very well. no other tape or glue was dong the job. a neighbor with same problem used this stuff several months ago and his patch is still holding. not sure how much punishment this stuff will take (moderate climate here, san fran, and no rain for a few months) but time will tell. will keep list posted. art, '91