Probably not going to find them unfortunately. I have not seen tile like that in a very long time.

Try do do a google search maybe for vintage tile. Otherwise it will have to be replaced with new.

I was afraid of that. do you know what design the stripe is in? would that be considered mosaic?

I do not know. It is not a mosaic. Mosaics are installed in sheets in small sizes unlike what you have. It looks like it is from a collection where the main floor and the smaller diamonds go together.