Mike-
yes - you use an equal measure of pt/pd and FeOx. You can vary the proportion of Pt to Pd to alter the look of the print. It is challenging to do a pure Pt print, for a number of reasons. You can possibly get away with it when you've done some printing with Pd prints to get Pd into solution in your developer.
As others have said, just toss that old FeOx and order some new from Bostick & Sullivan. Your life will be infinitely easier working with fresh FeOx. Take the FeOx #2 and throw it as far as you can into the nearest landfill of your choosing. Forget that it exists as an option. Yes it works, and is "ok" for a total newbie wanting to learn the process, but after you've made two or three successful Pd prints, you should never use it again. Take a look at the Pd and Pt/Pd prints in my gallery here on APUG to see some examples of prints made with Na2 as the contrasting agent.
If I recall correctly, I used 1 drop of the 5% solution of Na2 with this one -
(there was a url link here which no longer exists)
Matt is measuring in ml of fluid - I'm doing the old standby of drop counts, but I'm mostly coating 5x7 or 5x12, with the occasional 8x10 or 7x15 print, so I'm using much smaller quantities, and I'm not aiming for precision, just repeatability. As long as you use the same dropper every time (separate dropper for each fluid - don't want to contaminate them!), you'll have enough repeatability to control your process.