I don't see a lot of ИН-2 based clocks. I tried to make mine as compact as possible. Unlike Patashnik, it multiplexes the tubes so there's only one ИД1 and ATmega8 has enough pins plus a few more to spare.
IN-2's are not very suitable for clocks, perhaps, because of their tunnel vision. View angles for the "deep" digits are very narrow. The tubes are small, but it's impossible to make very compact displays with them because their cylindrical shape doesn't allow for rational use of space.
Project writeup: sensi.org/~svo/satashnik