While examining the various publications dealing with Dinky Toys, DINKY TOYS AND MODELLED MINIATURES, THE GREAT BOOK OF DINKY TOYS, COLLECTING DINKY TOYS, the Ed Force Books DINKY TOYS as well as the various John Ramsay BRITISH DIECAST MODEL TOYS CATALOGUE, all quoted 1964 as the introduction date for the 900 Site Building Gift Set. The original detailed publication compiled by Cecil Gibson HISTORY OF BRITISH DINKY TOYS 1934-1964 includes the set but has no introduction date.
In fact, the 900 Site Building Gift Set (frequently quoted as 900 Building Site Gift Set) was released at least twelve months earlier in 1963. It is even possible that the set and the others issued at the same time, were available for Christmas 1962, as it would be logical for Meccano to make the most of the "high-spending" parents and aunts and uncles for Christmas presents, especially in view of their quite high prices. However we can only go on documentation that confirms a date and these are below:
The above is from the 1963 Catalogue for the UK, 11th Edition.
The above is from the 1963 Catalogue for Australia, also 11th Edition.
The July 1963 issue of MECCANO MAGAZINE finally makes reference to the release of a number of Gift Sets that would have included the 900 Site Building set. These sets were 121 Goodwood Gift Set, 122 Touring Gift Set, 123 Mayfair Gift Set (specifically mentioned in the Meccano Magazine) 298 Emergency Services Gift Set and 900 Site Building Gift Set. All except 900 have the correct year in the previous quoted publications.
The 900 Site Building Gift Set is extremely rare, and in recent years, only two have passed through an auction. Both sets have a different Blaw Knox Bulldozer. One has the usual late issue in lemon, with the other having the rare 961 with a red plastic body with silver engine details.