I have fitted the same OEX starter to my 101 a few times now.
They have a reduction drive which the earlier rover ones did not and work very well.
I tend to go though starter motors not because the starters I am fitting are not good, but because of the hard life I give them.
The fan picks up water if crossing a creek at speed and drowns the civie non water proof distributor I have fitted.
If crossing a creek slowly, anything above the front tyres is the same height as the sparkplugs.
Many a time I have purposely cooked my starter and used my batteries to drive a dead wet motor 101 to dry land.
The crank handle works well after that .

