Lovely tiles. Red very common, beige fairly so, from reclaimers or spot
the ad in Ad mag etc, but usually 6 inch. Coud be cut to size - edges
rounded off with diamond block etc., Same with the blue with the
nearest match you can get but probably new only.
If you have a lot to cut you could take them to your nearest stone
specialist - (granite worktops etc) as they may have a diamond table
saw.
I thought it was raw linseed oil used, half and half with turps?

cheers

Jacob