I guess I'll order new caps then! Thanks.
About the jfets they are the same make and model so to say, but I've read that their specs can differ a lot (minimum cutoff voltage undefined, typical 3v, max 8v meaning its cutoff voltage could be anything in between >0 and 8v) so for This usage even same device number fets should be tested and matched. My wonders on this subject is whether this kind of mismatch means unusable or just crappy.
I bought a few more than I needed to be able to test around but that plan won't pan out well if poorly matched fets give zero output.