Moses tested FeLv+ and FeLv- I'm confused!

[Lee Evans]

We recently rescued a tame "feral" cat from an apartment complex where people move out and leave their cats to fend for themselves.  I named him Moses.  Since he comes from an area where all the feral cats tested negative on their combo test, I wasn't very worried.  I took him in for his free spay and vaccine and because he was tame, I had him combo tested because I was going to foster him at my house until I could get him adopted or into another foster situation.  Unfortunately he tested positive for FeLv.  I really couldn't believe it and the clinic where he was neutered has been known to make awful mistakes so I took him to the vet I use for my own housecats and he again tested positive on the ELISA test.  I boarded him at the clinic while I discussed the situation with my rescue partner who had been the one to catch him in a cat carrier.  We decided to do the IFA test immediately rather than wait 3 months and test again with the ELISA.  Three months in a cage in a clinic is not the way to make a cat happy and it's expensive.  We do NOT kill cats who test positive for FIV or FeLv.  So the IFA test was done and it came back NEGATIVE. We were happy.  My vet called Texas A&M.  They told him that if the IFA was negative, we should consider the cat negative.  Just to be sure though, they said, keep him isolated for another month or two and then test again with the ELISA.  At this point I wanted to scream.  After that, my vet mentioned a test called the PCR.  A friend googled it and found that it tests for FeLv that might not show up on either the ELISA or the IFA.  Unfortunately, Cornell University Laboratory doesn't do the PCR.  It's popular in the UK but apparently hasn't taken hold here in the USA.  Does anyone have any experience with this test and also, what am I supposed to do with Moses?  Should I consider him FeLv+ or negative?  I took him home and isolated him in a spare bathroom.  I only have one bathroom left now.  If I get another cat in to recover for TNR, I'll have to build an outhouse for myself.  Sigh.  Any answers will be greatly appreciated. Incidentally, Moses is a healthy, shiny-furred black cat with an excellent appetite.  He's about 2 years old.  I have his "wife" and son who both tested negative in the ELISA.   Lee