If you need a replacement part for your Mini Starter, here's where to find it.  Pick from the following:

Starter Solenoid

Drive Shaft Tube - 8" - 10"

Drive Shaft Tube - 10" - 12"

5/8" OD Shaft, 5/16" Hex, 3/8" Square

5/8" OD Shaft, 3/8" Square, No Socket

5/8" OD Shaft, 1/2" Square, 3/4" Socket

5/8" OD Shaft, 1/2" Square, 15/16" Socket

5/8" OD Shaft, 3/8" Square, No Socket

5/8" OD Shaft, 3/8" Square, 17mm Socket

Please double check to assure yourself you're ordering the correct drive shaft.