Vintage Synth Repair

Hi Guys,many years ago(34 to be exact) I built the Clef Products String Ensemble from articles in Practical Electronics.This was one of the best analogue string machines I have ever heard but I sold it shortly afterwards to raise money to build the Clef Piano.I now have the urge to go back to my youth and build it again.I've managed to get hold of the old magazines and nearly all of the parts but the ones giving me problems were the BBD chips and the top octave generator.I've now got the TDA1022 BBD's but can't find  the AY-1-0212 top octave gen.Does anyone out there have one or know where I could source one.As a last resort I could use the one out of the piano but I don't really want to keep swapping it about.Could I slave the O/P from the piano tone gen to the string ensemble via an extra set of buffers to the divider ccts as I am thinking of housing both instruments in the same cabinet using the same keyboard with an extra set of key contacts.Ideally I would like it to have its own tone generator but that depends on if I can get the chip.Any help gratefully accepted Regards Colin.