UK, 1791

Joseph Priestley's Birmingham laboratory was destroyed by rioters and fire in July 1791. Assuming the insurance claim's weight avoirdupois,

1791: 1 Troy Ounce platina (UK: 70% ore, retail purchase) = £0.3291
1791: 1 Troy Oz. Pt (UK: 70% ore, .999) ~ £0.47