Just add a few vintage strings here and there either from a Logan/Solina/Farfisa/Yamaha ....
Of course one mustn't forget the Elka Rhapsody 610. Foxx sailed through this on Systems of Romance. It is my understanding that the strings on Metamatic came from the Polymoog, Yamaha CS80 and the Farfisa Syntorchestra or Soundmaker.
Another fine string machine/organ is the one used by JM Jarre on his early material, the Eminent 310U with the Electro-Harmonix Small Stone phaser. BTW the Solina was an original product by Eminent which was later sold as an ARP.
I've a weakness for string machines.
Chris C