I had some corduroy trousers in this colour in 1969 which may have been not too distant in either shade or time to Corgi's colour choice for an MGC GT. There were two colours: a black and yellow and this, more friendly but just as odd, orange. Both had black interiors and were, I believe, the only model that came with a black suit case.
Both are quite rare and this is the least common of the two. My stock example is in good condition with just a few marks on the paintwork but otherwise looking very fresh. It is almost the same cast as the MGBGT #327 but with a bulge at the front in the bonnet.