Thanks to both Rardi and Onecoolair! I'm going to take both your advice and not even try the thicker overlapping areas of sailcloth, reserving those areas for hand sewing. Don't want to tax my wife's machine at all. I have the heavy needles and uv threading from sailrite and will get a hand awl set as well. May not be the way I wanted this project to go, but hey! I'll get experience with both machine and hand repairs this season!
And will save up for a real machine for next time round ;-)
And will save up for a real machine for next time round ;-)