I had finished fabbing up my shiftrod last night (2 u-joints and a buggy shift rod shortening kit, using modified stock T1 shiftrod) and I can confirm that the Scat Dragfast shifter does work with the 901 tranny.
2-5 gears are where stock 1-4 gears are on a T1 gearbox. To access 1st on the 901, I pull up on the reverse lockout and shift ( to where reverse is on a T1) and reverse on the 901 is straight ahead of 1st.
Looking forward to the snow melting now so I can drive !!!
Sandeep