60's concrete double roman tiles

[Kris]

30 -40 years ago loads of houses were built with concrete DR's which were originally coated with red / brown granules which have weathered away. They now look a grey concrete colour with loads of moss and lichen.

I have tried all the local reclamation yards but they only keep clay tiles. Any suggestions for matching other than taking originals off the back of the house to put on the front and getting some new red ones for where it doesn't show so much.?

Chris