Great idea - should be easy enough? I always struggled when making vinyl stickers as the pressure/depth has to be perfect to cut the top layer but not the backing sheet. I guess the only issue would be to make sure that the gasket stays with the waste material and doesnt get chewed up as the plotter arm moves back and forward? might be worth tacking it down to a sheet of card or something with a pritt stcik or something not too permanent? Awaiting results....
I'm the other way round as I make adhesive labels every day and am used to "kiss" cutting through just the top layer. I'm hoping the knife in the plotter will cope with the thicker material ok. Almost finished recreating the gasket in vector form in Illustrator, will do the first test soon and report back (Might use your tip on sticking the gasket paper to a backing sheet - that'll at least protect the rubber cutting base)
I started by using the old gasket as a template, however I've noticed that the gasket itself isn't very accurate. I've now made an impression of the top of the carb with some paper and am doing a new drawing to get an accurate gasket. Good job this is a hobby; don't think I'll do it for a living!