Yes, I think the traditional 85Kg liveweight being pork and 110Kg plus being bacon must be an older guide.
As far as I can see at the abattoir the majority of commercial porkers are away smaller than this.
I'm sure I read that Berkshires make the best pork around 55Kg liveweight (might have been 'Practical Pigs')
I'll maybe give my pal up in the commercial piggery a phone and ask him weight/ages that they send to slaughter. Surely it'll depend on what the 'consumers' ie. supermarkets & wholesallers are looking for ?
From my point of view they go when they look ready, weighing up how much they've cost, how much more would be gained by running them on a bit longer and how many times they try to escape
It's finding that magic point where you'll turn a (bigger) profit, instead of breaking even............ and that's not always 85Kg.
Karen