Re: Or your best solution is...
"Gotta spend the money on a purpose-built PC to use as a media player"
Really not a solution to the problem at hand - I mean it solves several, but brings up several more.
And I don't need yet another full blown machine running - OpenELEC on a RasPi would be an ok solution, except that it likely doesn't support half the things the TV does, and means I have to deal with more weirdness when I do stuff which isn't coming over that particular cable.
If I could actually buy a dumb TV I would - If nothing else I could upgrade the source independently of the display.
But the TV sits on a sewer network, as far as it knows it's the only device on the network, and there are no inbound connections happening.