My clock building habit is apparently as bad as ever. This time, it was inspired by a stash of Burroughs B5092s, so I needed to vertically align it. Also, since I wanted to make it as small as possible, I wanted to keep nearly everything surface mount, so I abandoned the idea of using 74141s in favor of standard BCD to decimal converters plus some external drive transistors. No need to multiplex since I'm only using two tubes, so this design is actually pretty straightforward.
Almost everything about this design is ripped straight from the single digit clock, so not much more to say than that. You might be interested in the code and the layout. If you just want the precompiled hex for programming your pic, you can choose from three different versions: ( 60 Hz | 50 Hz | 50 Hz / 24 hr )
No pictures of the assembled board, but here's the circuit and the layout.