US: Hotel issue airmail labels

Here are the airmail labels issued in USA from various hotels.

Year: approx.1955, Gummed. Günter Mair's catalogue no: - USA-C-154, imperforated, blocks, issued
by Hilton and Statler Hotels, dark violet-blue or dar-blue or blue/orange-red/white, 2**

Blue

Dark violet-blue

Year: approx.1955, Gummed. Günter Mair's catalogue no: - USA-C-156, imperforated, blocks, issued
by Hotels Statler, grey-blue or light grey-blue/orange-red/white, 3***

Grey-blue

Light grey-blue

Year: approx.1955, Gummed. Günter Mair's catalogue no: - USA-C-162, imperforated, blocks, issued
by Hotels Statler, violet-blue or dark blue/red or grey-red or bright red/white, 2**

Grey-red

bright red

Year: approx.1950, Gummed. Günter Mair's catalogue no: - USA-C-179, imperforated, issued by
Robert Meyer Hotels, orange-red/dark violet-blue/white, 4****

Year: approx.1950, Gummed. Günter Mair's catalogue no: - USA-C-180, rouletted V, horizontal
strips, issued by Hotel Muehlebach, Kansas City, Montana, dark blue/orange-red/white, 4****

Year: approx.1950, Gummed. Günter Mair's catalogue no: - USA-C-186, imperforated, arrow shape
issued by Hotel Commodore, orange-red/dark violet-blue/white, 4****

Year: approx.1955, Gummed. Günter Mair's catalogue no: - USA-C-472, imperforated, blocks, issued
by Hotel Pennsylvania, blue/light grey/orange-red/white, 3***