Miniblinds don’t last forever:
The plastic frame failed at the pull cord opening, obviously a weak and, alas, non-repairable point.
A quick trip to Lowe’s produced a new miniblind with mounting hardware completely different from the old one. This came as no surprise, as every new miniblind differs from all previous ones; miniblind mounting hardware is not strongly conserved.
The broken frame fit into the plastic end caps mounted just beyond the scarred paint marking the bracket location required for the previous miniblind:
Note that the caps mount with a single screw in the homebrew bracket’s face, which has two holes to match the previous-previous cap.
Also note how the curved moulding strips around the 1955-era windows in this house do not fit any contemporary miniblind hardware, thus requiring Quality Shop Time with every installation.
Although the shiny new hardware had two slots, they neither lined up with the existing bracket holes nor extended quite far enough vertically. I lined things up, marked and drilled a single midline hole in both the new hardware and the old bracket, and reused the old screw and nut:
Moving the bracket back to its previous-previous location exposed the scarred paint under the previous position:
Fortunately, it’s hidden by the installed miniblind.
That was, all things considered, easy …
The Smell of Molten Projects in the Morning 
I do that particular operation a lot at my day job, since broken blinds are one of the most common dorm maintenance calls.
It’s been about two years since the brand we favor replaced the old style square bracket mounts–which could be reused for years–with the metal hangers you picture.
It happened when the blinds went cordless (an innovation I heartily endorse, BTW.)
Unfortunately, there seem to be at least three different metal hangers–one metal and plastic (which is easy to distinguish) and two styles of metal ones which are visually very similar, but incompatible.
There are nine and sixty ways of constructing miniblinds
And every single one of them is diff’rnt!
This is the first cordless one I’ve installed and surely the next will be just slightly different. None but thee and me will ever notice, of course …
Window blinds are a wet dream of a pedantic spring cleaner.
Indeed! A quick pass with a vacuum brush is as good as it gets.
I lust after the variable density / polarizing windows found in SF stories …
Right?!
As with so many things: the future is already here, it’s just not evenly distributed …