These should be okay as the information is freely available.
However, those for which you have to pay to access the records (FMP, Ancestry etc) are not allowed. This is because you would be posting in the public domain information for which there is a charge.
I also wondered about that old chestnut - copyright. TNA are very twitchy about their stuff being reproduced without permission. Even Ancestry and the rest have to reference TNA in their images.