I still want to start a BB for "Casino Other Stuff" although it seems to be fine here, so why bother as long as no one minds? But we could discuss stiring sticks, keno papers, ashtrays, ice buckets and postcards?

Here's something I put together, more for myself than anyone else, but now it's a standard file for when the question comes up. Hope it helps.

PP Postcard Archaeology Helper

Arcade Cards - postcard size, but plain back.
Chrome - Any card after 1939 with a shiny paper surface.
Deckle-edge - ripple or serrated edge cards
Linen - Postcards from 20s thru 50s using textured cross hatched surface.
Real Photo - Actual photo on photographic paper, not a printed image of a photograph.
View Cards - Cards that feature cities and places within cities.

The Amt. of postage can help date the card.
1872 (1 cent), 1975 (7 cents),
1917 (2 cents), 1976 (9 cents),
1919 (1 cent), 1978 (10 cents),
1925 (2 cents), 1981 (12 cents),
1928 (1 cent), 1981 (13 cents),
1952 (2 cents), 1985 (14 cents),
1959 (3 cents), 1988 (15 cents),
1963 (4 cents), 1991 (19 cents),
1968 (5 cents), 1995 (20 cents).
1973 (8 cents),

USPS Zipcode instituted in 1962
Extended Zip for automation added 198?

Phone Numbers:
Where four or five numbers until ????
Dropped Exhange Names in 195?
Introduced direct-dial Area Code + seven numbers ????

Using a phone number to date a card can help, but many smaller towns and companies used four numbers, well past the Bell System standard adjustments.