[gt39.5]

They let SOME replicas vintage race. The spyder in question used to belong to Fran Kress, the owner of gt40p 1054, who chose to race the spyder rather than 1054. Both cars are painted identical and outfitted similarly ( IE the rear deck scoops). There are not that many spyders around anyway, so it is something different to look at at least.
HSR's(Historic Sportscar Racing,ltd.) official policy is no replicas, but they do tend to allow them especially if the driver has several other cars (original) that are also entered on a regular basis, such as is this case.
SVRA (Sportscar Vintage Racing Association,ltd.)officially allows certain replicas, along the same lines as HSR
,such as a Ferrari 330 2+2 rebodied as a GTO, or an e-type, rebodied as a D type. The cars must be constructed axactly as the originals, so no fiberglass Cobras for instance, Or V8 Ferrari P4's.
This is my understanding of it all, and I may, as always, be wrong.