1978D (Trial ?) Bouquet

Possibly this was a trial design because it differs from the regular weight. The 3 flowers are set on a translucent blue ground as opposed to a black ground and there is no bud on the left-hand side of the bouquet. The weight is cut with a top facet.
The base is concave and polished and, although it has a Perthshire sticker, there is no P signature cane, which would indicate, perhaps, that it was a trial or prototype.