It's unfortunate that you're the wrong side of the Atlantic, I have quite a large supply of CD-4, CD-3, CD-2 and various other colour developing agents, some of which I'd give away. Most are going to a UK darkrom supply company.
Claire, are you trying to mix your own Flexicolor (C-41) developer? If so, there are a lot of bad ones published that can lead to inferior results. The same is true of published E6 formulas. Please make sure that you don't ruin good negatives. Test your formula by making enlargments of test objects first to insure good color, good curve shape and good sharpness.
And, please don't try to use it for color paper. Pat Dignan, many years ago, published data showing how it degraded dye hue and dye stability when used in color papers.
I use the one put out by William Laut. There is a different set put out by the Britsh Journal of Photography. I know a few people using the Laut formulas.
What I did to prove the formulas worked well enough was expose two rolls of film under the same conditions. One got commerically processed. The other I did. My enlarger settings didn't change at all between the two.
Now I only mix my own colour developer. I've no personal expierence with the bleach or fixer formulas. But the developer is what goes bad quickly and benefits from home mixing most IMHO.
Nick, the formulas at the URL you posted are close but do not match those in the C41 and RA4 solutions.
In particular, the film 'blix' is low in ferric edta even for a bleach, and will not do an effective job of removing silver. A key interimage control ingredient is missing from the film color developer.
The paper developer is missing some ingredients as well.
They may work just fine, but why take a chance. The actual formulas have been published in the patent literature. I'm surprised that no one has just taken them and tested them and then published them. That would solve all of the doubt.
Even then, I would still buy the stuff ready made in kits. It really saves a lot of hassle.
1) The stuff is always fresh in what ever amount I need. I mix mine up just before loading the film tank.
2) I know with a stock of chemicals I can mix my own no matter what.
I don't use the bleach in the formula but others are and seem to be doing fine.
On the patent issue. Does anything really require Kodak to be 100% honest in those patents? If they patented a formula that was close to the right formula would that be okay? Can you even patent a formula? Isn't it just the process?
To be honest I find the effort to mix the C-41 film developer trival. No more effort then mixing up various parts of a kit. Once I got over the MSDS for Hydroxylamine Sulfate mentioning the stuff goes boom I've been okay.