A. Lange & Söhne

Hello, Does anyone know when ALS made the transition from the brushed case side to polished for the 1815 Up/Down? Thanks

they didn’t change it at all: while the rosegold models have polished case side, the others ( wg and platinum ) brushed.

I wonder what the rationale is for the two different case finishings. I know the 1815 line makes reference to pocket watches in terms of aesthetics, but it seems arbitrary to have one polished and one brushed.

Until 2015, Lange polished all rose gold middle cases, across all models. This was unique to rose gold; Lange brushed the middle cases for all other metals. Lange said they polished (vs. brushed) the middle of their rose gold cases because for some reason... 

I knew there would be a good reason. I can't believe I never made the connection all these years. And thanks for the tip regarding the caseback; that also makes sense as well now.