You've got a pretty rare car there, as the optional 289 4V engine fitted to the D code cars wasn't sold in large numbers. It was only available from April to September 1964.
Early versions had a generator instead of an alternator, and the oil filler protruding from an aluminium timing cover.
If it's still got the aluminium water pump housing, these were prone to rotting away internally, so keep an eye on it for leaks.