GTD40 fuel pump

I have a GTD40 from 1989 with EFI injected system. Fuel pumps consist of a high pressure pum that feed to the injection ramp. The high pressure is in turn feed by a single unit/double pump low pressure ( a small black double pump) that carries fuel from the tanks. Aswicth allows to move from one tank to the other.

Does anyone have the same system ? Does anyone know what this low pressure /double pump (small , black plastic one) is ? make ? brand ? where to buy ? has anyone replcae dit already ? if yes by what type of pump ?

Many thanks for your help.
Best Regards