I am heading up to the darkroom tonight -- I'll get the info.
The Ferric oxalate (especially with the Pot chlorate) do have a relatively short shelf life (those from B&S last about 6 months, and that is the longer lasting stuff). The other chemicals will last a long long time. The ferric solutions are relatively cheap, also. Since the platinum salts are the costly one, it makes sense to buy fresh. No sense taking the risk of failure and disappointment with bad ferric salts.
So I suggest getting fresh Ferric oxalate solutions and buying some palladium salts, too. Then do a mix of platinum and palladium for your prints. I like the color and contrast of a 2:1 or 3:1 mix of platinum : palladium. This will stretch out the platinum supply you have. You can get paper from B&S, too -- and they can answer any questions on the phone when you order...great people!
Try to make negatives that do not need, or need little of, the Ferric oxalate w/ the Pot chlorate (solution #2). If the neg will print on silver gelatin paper with no contrast filter, it needs more contrast for pt/pd. Your prints will look better as too much #2 will cause some graininess to appear.
Back to you later tonight...