I sort of agree with the net result of Darren's comments, except that T70 suspension arm dimensions are different from MK I to MK II to MK III. MK I are an inch longer in the rear but the wheel is in the same lateral location. In other words the suspension pickup points move closer to the centerline of the chassis nd the arms are of a different design on the MK I.
MK II and MK I are the same in the front but MK III is longer in the front but again the wheel is in the same approximate location but changed a bit for vented rotors to clear the upright and spring/damper. MK I, II, and III uprights function with the same offset but have slight difference such as stiffening ribs etc. Rear uprights similarly. MK 3b front and rear uprights use deeper offsets. You could divide the wheels into deep offset and shallow offset for both front and rear with the deep offset being for the T70 MK3b , T190 series Formula 5000 cars, and T160 series cars. The shallow offset family of wheels would be for the T70s MK I, II, and III and also for the T140 series Formula 5000 cars.
Just looking at deep offsets there are 4 front rim widths (10, 10 1/2, 11, 12) and two rear rim widths (14,17). The shallow rim widths front (8, 9 1/2,) and rear (10, 12, and a rare 14 such as on the Penske Can Am T70s).
There are 4 required offsets. Shallow front and rear and deep front and rear.
Shallow front offset is 2 3/8 and shallow rear is 4 3/8.
Deep front offset is 6 3/4 and deep rear is 7 1/2.
There are variations galore that result in 1/8 - 1/4 differences in these numbers.
I typed this from my phone and from memory so sorry for the garbled info but maybe it is helpful.