Since this plant - Abutilon - is not a maple at all, I'd suggest you look for seed of it on the Perennials, Shrubs or Tropicals forums or their associated exchange forums. And since a good many are hybrids or named forms and unlikely to come true from seed, you might want to seek out cuttings rather than seeds.

FWIW, the correct place to ask for seeds, cuttings or other plant exchanges/trades is on the Exchange forums.
http://forums.gardenweb.com/forums/exchind/