These are all plates that have been sold since mid 2013 (and before) by English Ebayer worldplatesuk who has now changed his name to agaplatesuk.
These are a batch of older UK and Jersey motorcycle plates including one he claims is an RAF motorcycle. Most of them are fronts and there is one back. Many, many years ago when this type of plate was required, the registration would be properly hand painted on, stickers would be used or a small curved pressed plate would be attached on each side. This kind of crudely painted plate was just never seen on the roads of the UK.
Some of these plates have obviously had the registration painted over the rust on the plate, one has the registration painted after the bolt was removed that mounted the plate and a couple show signs where the pressed curved plates have been removed before the registration was painted on.
To me, they all look like they were painted by the same person in a garden shed somewhere. He regularly sells genuine, pressed, curved front motorcycle plates without one of these mounting plates.
I have also included a hand painted Italian plate he has for sale that looks like part of the same batch. Again, genuine Italian plates never looked like this and it is so amateurish that it could even have been a JDA fake originally.
Very suspicious plates from a well known seller of doubtful plates and you should think long and hard about buying any of these.