Front hubs on fourtraks


I have been told that the left side front autofreewheel hub on my '94 TDS fourtrak is missing a locating pin (one of two)due to having been incorrectly refitted at some point in its existence.
Whilst this is not affecting its normal use out of 4x4. there is a risk that the hub could fail, when in 4x4!
My question is are there any of these hubs available? Do I have to visit the main stealers? Does anyone out there have any advice?

I know, questions,questions.
Thanks in advance