Ok I found a listing stating a running time of 97:08. Since the US disc runtime is 101:15 (very close to 25/24 + 24/23.97 slowdowns) I assume that running time listing is correct. I've approved Jason One's format submission too.
I still would hope a member from here said specifically enough : "Yes I have the UK Spearhead and I tested its native output and my display/player says 1080i 50Hz"
but hopefully the updated spec is correct. (I don't have the Spearhead disc)
I think we have most of the Doctor Who and related US/Canada vs UK and other 50Hz countries' specs correct but there's so many release iterations.