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Taking it back to brick at least a few days for one person with a scutch comb SDS attachment.
Then there's the cost of disposal.
From the look of it, it will be lime plaster, which is a magnitude more pleasant than stripping gypsum to brick.
How would you have it re-plastered? With lime would be the purist way (ask @Señor_Bear about that), and likely the priciest, gypsum to brick is doable, or you could dot & dab tapered boards and just paint / paper them for cheap & effective.
Also what @absurdbird wrote - why bother? If it's in reasonable nick, just skim it.
@absurdbird Do you know what a rough cost would be to take it all back to brick and replaster? It's a hallway wall in a victorian terrace house.