Many years ago I built two 7 segment clocks with these chips.  Has anyone got any floating around in their junkbox?  These chips are not made any more, or any equivalent as far as I know, unless anyone can advise me otherwise.  Both these chips had multiplexed outputs and used transistor drivers for the displays.

I've emailed a colleague who has a vast stock of electronic ephemera!   You may be lucky

Maurice
 

OK, thanks Maurice, I will wait to hear from you further.  Any other clock chips will do, they do not have to be the ones I specified as long as they have 7 segment outputs.  NTE2060/1 are fine but they do not have multiplexed outputs and these are also getting difficult to find.  I could use  BCD chips and then BCD to 7 segment decoders but this involves too much effort.