Bonding + finish plaster or easifill is the standard approach, it's pretty easy to get it done quickly and unlikely to create too many problems. Sounds like you might not be happy unless you do it in lime though.
Just a thought, I admire your endeavours, but it may be easier to get a plasterer to do that - if you have a look round locally and see if any work is being done, perhaps a helpful plasterer could pop round with a bucket of plaster and fill that for you.
As I said, just a thought.
Well done. Then bonding makes it pretty easy right?
Multifinish is quicker than Easifill for the top coat but a little bit harder to handle and you need to buy bigger quantities. Easifill works fine if you get the mix right.
Bonding + finish plaster or easifill is the standard approach, it's pretty easy to get it done quickly and unlikely to create too many problems. Sounds like you might not be happy unless you do it in lime though.