Constructed in china cabinets were rather ordinary in vintage kitchens and not only in luxury houses ) I have lived in three comparatively small 1920's flats that still needed them. And, when the kitchen did not have them, occasionally the dining room or butler's pantry failed.
The built-in cabinetry in the photograph is marvelously complete, but it is a shame that the door pulls were substituted. Although they're coated in paint, at least the hinges are all first.
Some built-in china cabinets definitely moved into the landfill once the homeowners remodeled. Luckily, lots were also uninstalled also. I have seen them in flea markets, re sell stores, and thrift stores. If you do not locate what you'll need at any of these, your very best bet is an architectural salvage store.
image source: pinterest.com