Repointing - lime or cement

[WasteOfPaint]

We recently bought a house and the survey report says a small amount of repointing is needed on one wall. Specifically, it says the gaps should be raked out to a certain depth and repointed with lime based mortar. However, the existing mortar is cement (1950s house). So if we followed the surveyor's instruction, this would be a small amount of lime mortar on top of the existing cement. Is this beneficial/a good idea?

I do not think you need it repointing in lime, it will have a cavity.
i think “ Diyextension” is spot on and they have half looked at it and assumed it was original Bath stone.
Pre -1920 houses of solid brick/wall construction can have issues with moisture being trapped in the walls and subsequent damp issues, also old soft bricks will spall as Lime contracts with the weather and Cement is not as flexible.
whoever repoints it would probably use a bit of lime to help with the elasticity.
Good luck.

Yes it definitely has a cavity. I think you're right about the surveyor - although it's weird that they would have identified it as a 1950s build (and it's a very typical ex council house of that era) and yet gone down that line of thinking about the mortar.