[INDOLOGY] Tilopa's Mahamudra Gangama (also called the Ganges Mahamudra)

[James Hartzell]

Hi 

Does anyone know of an extant (ideally digital edited) Sanskrit text of Mahamudra Upadesa Gangama (also called the Ganges Mahamudra)? 
A colleague not on the Indology list asked.

Cheers
James