Hey to address the rust issue no matter if you go with Tom's mod or with OEM replacements, send the shaft to Calico Coatings to get the splines micropolished and coated with a composite Teflon that has corrosion/rust inhabiter.

ceramic coatings, teflon coatings, thermal coatings solutions with Calico Coatings


You will never have a problem again. I work for them when I'm home from school and they are an industry leader. Its worth the peace of mind for a hundred or so bucks to have done. Plus they do all kinds of high performance coatings. Their quality is 2nd to none.

The micro-polish makes the splines less abrasive to counter act one eating into the other, and the Teflon coating reduces friction co-efficients and addresses the rust issue. Just smear some Red Line synthetic between the two and bingo.