Chosen Solution
As far as future upgrade prospects, a new logic board from iFixit is ~1/2 the price of a new MacBook Pro. So, could one retrofit, say, a mid 2010 unibody 15” MBP with a late 2011 logic board (including new heat sinks and new battery)? I noticed the heatsink screw points are ever so slightly skewed and that the battery connector has changed, but most everything else seems about the same.
You would still need a means to cut a hole in the case for the TB port. I think your going to far here. Too many chances for problems. Best to sell your current system and buy a new (used) system with a TB port if your really need it. Frankly, the cost of TB devices are still very high and don’t offer enough to warrant getting them quite yet.
