unknown mammillaria

hi,
I am a new member from Greece and i would like to ask for your help in order to identify those mammillaria.
I don't know if these photos help on this-if you need better/different close-ups let me know.

1.


2.


3. (two photos)



4. (two photos)



5. (two photos)



thank you for your help!

i think that the first could be m.parkinsonii
2 - mammillaria rekoi ssp leptacantha
3 - mammillaria matudae
4 - mammillaria spinosissima
5 - mammillaria backebergiana

I agree with Maurillio, and am also a little unsure about 1. It could be M. parkinsonii, but it has characters also of M. albata . I know that this is a wide range of species, so would ask if ithas flowered for you ever, and if so what were the flowers like?

unfortunately i have not seen any flowers yet since a friend brought it to me almost 2 months ago.
if it gets red/purple flowers is m. albata?

Certainly M.albata has red flowers, so if it flowers like that, this could be a contender.....