The only RS turbo model kit that is commercially available is made by K&R replicas, they do both a series 1 and series 2.

K & R Replicas kits are well cast, if rather crude, metal kits. Usually accurate though occasionally a bit odd. Wire wheels of the self - assembly type. Decals, when included, often slightly yellow (typical of many English makers) but will bleach with exposure to u.v. light. Made in England.

All other models that I have seen are custom one off builds.