Horo_Traveler
975
I don't believe the Langematik Perpetual in Pt is in the current catalog
However, these are readily available in the pre-owned market. The muted grey dial variant was released first and later replaced by a shinier silver dial. The older models had a push button to advance all the PC functions in sync and the newer ones have a recessed push pin.
There are several other PC watches by Lange and many of them are available in Pt. Their website is aggravating to navigate, so you are best off ordering a catalog for an overview of the various models and variants. You should try these at an AD or boutique to get a sense for wearability and general connection to the watch as they have a rather different design sensibility than Patek.