Tennisone used to have a really nice .gif quite a few years ago of Lew Hoad serving. It was from the side and you could really see how far forward he tossed the ball.
There are quite a few black and white newsreel clips over here:
Type tennis forest hills
into the search engine and the first clip on the page is of a Davis Cup doubles match with Hoad, Rex Hartwig vs Tony Trabert and Vic Seixas. Clip 1617576_031 is of the 1956 US finals where Lew Hoad lost his chance for a Grand Slam when he was upset by Ken Rosewall.
The site is kinda weird because hoad
doesn't seem to bring any clips up and you can't link directly to clips.