John, go to
www.gunbroker.com and search "G3", and you'll find some occasional offerings of single pieces. I bought a used beavertail forend for something like $35.00 (I've seen them go for over $100.00). The one I bought is OD green; however, I'll paint it to match the rest of the furniture. If I find an original black forend, I'm gonna snap it up. With my large hands, the slim forends just don't feel right and they don't insulate as well either. As far as the PTR goes, you'll pay more for the
kurz model, but I almost went that way myself. Try
www.atlanticfirearms.com and/or
www.jldenter.com and you'll find something you like.
John, if you do go for the shorter model, you'll have a LOT more trouble finding the correct beavertail forend.