For 32 oz cans see Quarts and for gallon cans see Gallons.
I'll start off with some general hints and rules and then we'll get to specifics.These were used by a small number of breweries including Croft, Liebman (Rheingold & Liebmann brands) and Adam Scheidt (Valley Forge brand). They range from the very common to the very rare depending on brand and variation.They are all fairly rare and very valuable in good condition. For more on quart cans see the One Full Quart site.Look along the seam for the year on most Schlitz cans.Look and see if there is a tax statement on the can, along the lines of "Internal Revenue Tax Paid" or "Withdrawn Free of Internal Revenue Tax" if so, then the can dates before March 1950.These were used in 19 and were replaced by cans with a concave bottom and ribs that stuck out along the top in early 1937. 7 and 8 oz cans came into use about the same time with one exception, there is an 8 oz Fox Delux beer from the late 1930s.An odd sized can is not necessarily rarer than a 12 oz.Unfortunately I do not have the data needed to date a can by its state tax stamp. Sometime when a brewery closed another brewery would purchase its brand names and the new owner continued to use the old brewery name.Find when the brewery that filled the can was in business. For example, if you search for Christian Heurich, which made Senate Beer among other brands, you will find it closed in early 1956. For example, Baltimore's Gunther Brewery was purchased by Hamms in 1959. Is the can crimped where the body meets the lid and bottom? By 1967 few brewers still used flat top cans that had to be opened with a church key.Look carefully at the wording at the top of the can. 7 and 8 oz cans came into use about the same time with one exception, there is an 8 oz Fox Delux beer from the late 1930s.All other 7 and 8 oz cans date from the early 1950s or later.