Update: (after a while)

Finally my beige 2872A2M Touch-A-Matic works with matching color PC 4A Speakerphone. Rare kit of parts required for converting 2872 to speakerphone service is extracted from black TAM I’ve just received. That one will require some good repair: part of power supply board is burned out. But for now Speakerphone board is enough.
Thanks to Arthur for relaying this TAM to me.
Appreciate if anyone can share the SD of TAM set (2872A2M) or just PSB (power supply board). Will need it for repair.