If I have understood your query correctly Andrew, I think that it was probably Princess Michael of Kent who changed the band of the festoon tiara from a diamond one to a pearl one.
Princess Marina and Princess Alexandra both wore the tiara with a diamond base band.
In the early years so did Princess Michael, but when she changed it is unknown to me. I wonder if it could have been when she placed a diamond necklace above the tiara the City of London gave to Princess Marina?
Princess Michael with the tiara in the early years of her marriage. It has a diamond base.
Later the tiara had a pearl base.
--Previous Message-- : Has it been discussed before that this tiara : had is collet diamond base replaced with : pearls by Princess Michael? : : --Previous Message-- : There are quite a few threads now about the : Kent jewels and I find it all very : interesting. It is not so often we get to : discuss this part of the British jewels. I : am sure we would have had more chances to do : so had the Duchess participated more at gala : events. It is a shame she is no longer able : to or willing to take part. She used to be a : wonderful representative. What I did not : realise until today is that she has worn the : Kent Scroll tiara at least a couple of : times. And I thought I would share a couple : of videos showing her with this lovely : tiara: : : At the Independence of Uganda in 1962 (looks : like she wore it at two different events : during this occasion): : : : http://www.britishpathe.com/video/uganda-wins-independence/query/Duchess+of+Kent+Independence : : : At the Independence of Gambia in 1965: : : : http://www.britishpathe.com/video/gambia-independent/query/Duchess+of+Kent+Independence : : : :