Your driving concern at this point is the failure of one or more of your existing containers, which would be bad from a health and environmental point of view, beyond the mess and damage it would do in your darkroom. Clean-up and disposal would be a real headache.

What do you risk in transferring/combining your supply? There is some chance of cross-contamination, but if they are unopened I don't see much of a problem there.

Is there sediment/precipitate in any of the bottles? You might want to screen that out. Otherwise, have at 'er... and use the stuff.