237 Mercedes-Benz Racing Car (1957-60)

Some thing is hidden on this box. Does any one know what it is ?

Jacques Both the 238 D-Type Jaguar and the 239 Connaught Racing Car, have their model number in exactly that same position, with similar descriptive wording for the cars accomplishments. I am guessing that possibly Meccano (or the vendor who made the boxes) made a mistake on the model number for the Mercedes, in that area, and did not discover it until many, many boxes were already made. They then had no choice but to black it out. The size of the blacked out area looks to be just right for No. 237.Just my guess....perhaps others have a better one?Best regards, Terry