That is a tricky one.
I would definitely have pages up for each at the start, but with different content, even if Im forced to invest further to make it more unique.
Once the traffic for that brand name dwindles down, I would redirect it to the latest name.
Depending on the competition level, if it's not too hard, I would just stick with 1 page but make sure to mention the old name on the body (and even on the meta details if possible) It can rank just as well.
These are all assumptions. It's really a tricky position that needs to be analysed further. 

