+1 on everything Robert said. But, two little bits of additional information:
1. Automotive clear has a reasonably long shelf life and is not very expensive. Buy it and use it, it will be your best result. I have had excellent result in apply catalyzed clear over Rustoleum rattle can paint. The clear did not affect the Rustoleum at all and looks great. I used Rustoleum on my steering shaft and shift lever and will do the same of the steering wheel. All covered in catalyzed clear for durability.
2. There are respirators that are rated for isocyanates, so an air supplied hood/respirator is not mandatory, but not a bad way to go for sure. If you paint for a living, no doubt air supplied hood is preferred. But, for the occasional garage painter, an approved and well fitting respirator will do just fine. Heck, you even see the guys on the auto restoration shows using regular respirators. They do exist. 3M and Gerson make them as well as others I am sure.
