You could also call the Blue Cross (who helped James and Bob) when James was busking on the street and found Bob who saved him from drugs etc ...the Blue Cross healed the injuries the cat had and, I believe, did not charge him, You could phone them for advice or you could approach your neighbour just to ask if they had any objection to your taking him to someone as you are concerned about him ..that is if your neighbours are approachable ! Our neighbours cat decided it was going to live with us and our three cats instead of at theirs, We asked them if the minded if we paid for it to be sterilised, They had no objection, and we received a voucher for a reduced price at selected vets, from a cat charity, Sadly after a few years the little cat disappeared one night and we could never find him, he had a chip so we have to assume the worst. If you look on Facebook there is a group, James and Bobs fundraising ..they are extremely helpful in cases like this !"
Goof luck
I've got another 'keen'... Ouch!