I suppose that with enough work, a long forend could be created from a sported SMLE stock cut in front of the band. Do a splice under the band to get the necessary length, patch out the cuts for rear sight protector, barrel band screw, alter inletting, etc. Would be a lot of work for at best a second rate result.
A long stock sported in front of the band could be stretched.
Most stock carving machines use a pattern, which is traced with a stylus, which in turn controls the cutter(s). The pattern must be mounted to the machine. There is always the risk of an original stock being damaged or marked up if used as a pattern.