They look to me like the old Marley type tiles or perhaps Lino. I don't have much experience with them other than doing a test patch on this type of tile last year, floor stripper with a black pad, poly brush and a few coats of polish and they came up fine.
The ones I did were red and some of the colour bled from the floor probably because they were of a similar age to those above.
Apparently this type of tile may have asbestos on the backing so I would look into that if you do the job.