I just received an email from the Royal Collection Trust offering 24 hour priority booking for "Exclusive Evening Tours" at Buckingham Palace, Windsor Castle, and Holyroodhouse.
I'm posting in the Scotland forum because that's where I'm going next.
https://email.rct.uk/4SVR-TBEB-3C96BF98398180115KLL5A764B453584ED322B/cr.aspx
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