Hi,
I doubt that you can find much about the lend-leased Soviet PT boats, unless you can use Russian websites, since all of them were sent to the Northern flotilla of the Soviet Navy, which is one of the most obscure formations that took part in WW2, so I guess it's quite difficult to obtain wartime pictures of Soviet PT boats. However, as far as I know, all Soviet Higgins PT boats were 78 footers. There is an excellent website, where one can find their Russian pennant numbers, and here's the link:
http://www.warshipsww2.eu/lode.php?language=E&period=2&idtrida=1806