There are a number of differences between mini frontsubframes...
Real early 850 subframes had steel trumpets/later were alloy
850 subframes had different bottom arm bushes
Deluxe & Cooper S subframes have different hydro bags/different paint markings.
Leyland mini hubs changed steering arms at some point
Some subframes have bolts in the towers rather than studs/nuts
Early cars had a UNF thread in the rubber donuts/later cars had UNC threads
Auto subframes are different/wider & have brackets for sump guard
Later Moke subframes are different/have brackets for roo bar & captive nuts for sump guard & some have a steel pad welded to the top arm
Rover mini subframes are rubber mounted & have rarther large tower bolts
Im sure theres more too, eg - factory paint markings/colour of top arms (mostly black but autos seem to be painted grey) etc etc
I hope this helps
