je suis teuchter
I think those repairs are independent of the arch refurb works.I too have been pondering this each time I walk past. Will be interested in the reply.
I couldn’t see a heritage conservation statement on the planning database, but it’s not unusual for repair work to be done in traditional techniques and materials but not artificially aged to match the old, the rationale being that it will age over time. There might also be conditions against using reclaimed materials on a structure such as a railway viaduct.
If it has been stated - say - that only unsound bricks will be removed and replaced with new London stocks with weatherstruck lime mortar joints at the line of the original wall face, then the contractor might have some defence, since this looks to me to have been the approach. It then becomes more a question of the quality of the workmanship.
None of this means I like the look of it (I don’t), but seamlessness might never have been the intent.
They've been doing them all along the viaducts in the area, and mostly in the same incongruous style. For example if you walk along Milkwood road at the back of Herne Hill station you'll see quite a few bits at eye level.