I'm skimming some old plaster walls and in the process found that the original bonding stops too far up the wall for the new (shorter) skirting board. Also it's coming away a little so I've gone back to the brick a bit further up in places too.
Photo shows some of the state of it, Ignore the radiator.
I'm not keen to chip off and redo the entire wall so I plan to fill in new bonding at the bottom before skimming the whole lot.
My question specifically is:
Should I add bonding flush with the old surface
Should I add a layer of finishing/patching plaster on top of that to match the old top coat, then skim the lot?
All tips appreciated for this kind of job.