cat 303.5c cr starter and ign swt problem

I have to jiggle key around to get into start psn, and starter turns over slower than it should. (new battery) I cant find that model parts info tho have googled several tries, engine is Mitsu S3Q2-E1T. Was gonna try cat dealer here monday, but not sure they will give out parts# Lots of starters availible but none fouind for my unit. Any leads? I also want to replace rubber tracks, any Ideas of best place to buy them? I think I can get them on myself even tho I am a 75 yr old guy wityh injured shoulder :-) Thans in advance ffor your help. Charlie

cat 303.5c cr starter and ign swt problem