Here’s a diagram with part numbers for your RD 15. The P/N’s may have been superseded by new ones but at least you can take them to your OMC/BRP dealer if you have to buy the seals individually. This gearcase doesn’t look much different to later ones so you can compare the P/N’s to the ones given in the link. Click on a Sierra P/N in the link and the contents of the kit will appear, sometimes.
http://www.iboats.com/Johnson-Lower-Uni … _id.271288
